Loading [Contrib]/a11y/accessibility-menu.js
Research article Special Issues

Seismic response of RC frames equipped with buckling-restrained braces having different yielding lengths

  • Buckling-restrained braces (BRBs) have proven to be a valuable earthquake resisting system. They demonstrated substantial ability in providing structures with ductility and energy dissipation. However, they are prone to exhibit large residual deformations after earthquake loading because of their low post-yield stiffnesses. In this study, the seismic response of RC frames equipped with BRBs has been investigated. The focus of this research work is on evaluating the effect of the BRB yielding-core length on both the maximum and the residual lateral deformations of the braced RC frames. This is achieved by performing inelastic static pushover and dynamic time-history analyses on three- and nine-story X-braced RC frames having yielding-core length ratios of 25%, 50%, and 75% of the total brace length. The effects of the yielding-core length on both the maximum and the residual lateral deformations of the braced RC frames have been evaluated. Also, the safety of the short-yielding-core BRBs against fracture failures has been checked. An empirical equation has been derived for estimating the critical length of the BRB yielding cores. The results indicated that the high strain hardening capability of reduced length yielding-cores improves the post-yield stiffness and consequently reduces the maximum and residual drifts of the braced RC frames.

    Citation: Mohamed Meshaly, Hamdy Abou-Elfath. Seismic response of RC frames equipped with buckling-restrained braces having different yielding lengths[J]. AIMS Materials Science, 2022, 9(3): 359-381. doi: 10.3934/matersci.2022022

    Related Papers:

    [1] Aziz Belmiloudi . Time-varying delays in electrophysiological wave propagation along cardiac tissue and minimax control problems associated with uncertain bidomain type models. AIMS Mathematics, 2019, 4(3): 928-983. doi: 10.3934/math.2019.3.928
    [2] Yirong Huang, Liang Ding, Yan Lin, Yi Luo . A new approach to detect long memory by fractional integration or short memory by structural break. AIMS Mathematics, 2024, 9(6): 16468-16485. doi: 10.3934/math.2024798
    [3] Farman Ali Shah, Kamran, Zareen A Khan, Fatima Azmi, Nabil Mlaiki . A hybrid collocation method for the approximation of 2D time fractional diffusion-wave equation. AIMS Mathematics, 2024, 9(10): 27122-27149. doi: 10.3934/math.20241319
    [4] Abdulaziz Khalid Alsharidi, Saima Rashid, S. K. Elagan . Short-memory discrete fractional difference equation wind turbine model and its inferential control of a chaotic permanent magnet synchronous transformer in time-scale analysis. AIMS Mathematics, 2023, 8(8): 19097-19120. doi: 10.3934/math.2023975
    [5] Azzh Saad Alshehry, Humaira Yasmin, Ali M. Mahnashi . Exploring fractional Advection-Dispersion equations with computational methods: Caputo operator and Mohand techniques. AIMS Mathematics, 2025, 10(1): 234-269. doi: 10.3934/math.2025012
    [6] Junseok Kim . A normalized Caputo–Fabrizio fractional diffusion equation. AIMS Mathematics, 2025, 10(3): 6195-6208. doi: 10.3934/math.2025282
    [7] Rahmatullah Ibrahim Nuruddeen, J. F. Gómez-Aguilar, José R. Razo-Hernández . Fractionalizing, coupling and methods for the coupled system of two-dimensional heat diffusion models. AIMS Mathematics, 2023, 8(5): 11180-11201. doi: 10.3934/math.2023566
    [8] M. Mossa Al-Sawalha, Khalil Hadi Hakami, Mohammad Alqudah, Qasem M. Tawhari, Hussain Gissy . Novel Laplace-integrated least square methods for solving the fractional nonlinear damped Burgers' equation. AIMS Mathematics, 2025, 10(3): 7099-7126. doi: 10.3934/math.2025324
    [9] Nehad Ali Shah, Iftikhar Ahmed, Kanayo K. Asogwa, Azhar Ali Zafar, Wajaree Weera, Ali Akgül . Numerical study of a nonlinear fractional chaotic Chua's circuit. AIMS Mathematics, 2023, 8(1): 1636-1655. doi: 10.3934/math.2023083
    [10] Ikram Ullah, Muhammad Bilal, Javed Iqbal, Hasan Bulut, Funda Turk . Single wave solutions of the fractional Landau-Ginzburg-Higgs equation in space-time with accuracy via the beta derivative and mEDAM approach. AIMS Mathematics, 2025, 10(1): 672-693. doi: 10.3934/math.2025030
  • Buckling-restrained braces (BRBs) have proven to be a valuable earthquake resisting system. They demonstrated substantial ability in providing structures with ductility and energy dissipation. However, they are prone to exhibit large residual deformations after earthquake loading because of their low post-yield stiffnesses. In this study, the seismic response of RC frames equipped with BRBs has been investigated. The focus of this research work is on evaluating the effect of the BRB yielding-core length on both the maximum and the residual lateral deformations of the braced RC frames. This is achieved by performing inelastic static pushover and dynamic time-history analyses on three- and nine-story X-braced RC frames having yielding-core length ratios of 25%, 50%, and 75% of the total brace length. The effects of the yielding-core length on both the maximum and the residual lateral deformations of the braced RC frames have been evaluated. Also, the safety of the short-yielding-core BRBs against fracture failures has been checked. An empirical equation has been derived for estimating the critical length of the BRB yielding cores. The results indicated that the high strain hardening capability of reduced length yielding-cores improves the post-yield stiffness and consequently reduces the maximum and residual drifts of the braced RC frames.



    The present contribution is based on a geopolitical analysis method to describe whether and how the pandemic is changing the international scenario. According to John Agnew’s theory of the territorial trap, ignoring the reality of transnational threats leads decision-makers to imagine the world as a series of separate boxes and pushes states to make irrational choices [1]. The Covid-19 pandemic has created a tension between its global spread and the principle of national territorial sovereignty as a locus of political responsibility [2]. States have responded to the global challenge of Covid-19 with national solutions. In the medium term, from a geopolitical perspective, national isolation has prevailed over global solidarity. The perception that the risks caused by the spread of the virus could undermine national security and sovereignty [3] has led most states to isolate themselves by refraining from multilateral cooperation [4].

    The rapid spread of the virus seems to show how the international order, focused on borders and political-territorial spheres, is currently struggling to manage complex problems caused by factors such as innovation and the mobility of people, goods and information. The international health emergency seems to have accelerated the beginning of a new glocal era, based on a close correlation between the local and the global sphere. This article aims to analyse the causes, consequences and possible geopolitical scenarios of this phenomenon.

    In a short space of time, the virus spread quickly from the market in the Chinese metropolis of Wuhan to the rest of the world, thanks to the infection being spread from person to person. To this global change, states have responded with national solutions. At the peak of the pandemic, contrary to the instructions of the World Health Organization [5], more than one hundred and thirty countries closed borders or imposed strict border controls and banned from entering a selection of citizens from the outbreak areas of contagion. These “cures” are often worse than the disease.

    Restrictions on the mobility of citizens between and within states have pushed thousands of expats and temporary migrant workers to return home illegally, at the risk of helping spread the virus where it hadn't yet arrived.

    Many American entrepreneurs who were in Beijing on business bought plane tickets to the United States with a stopover in Japan in order to circumvent the entry ban imposed in the US on anyone arriving from China. The choice of some governments to publish blacklists of travelers considered carriers of the virus by reason of their nationality, has exacerbated forms of discrimination and racism, especially towards the Chinese and the Italian communities who in their respective hemispheres were the first victims of Covid-19. Even in the U.S. many Asians with American passports flocked to the gun stores, purchased pistols and rifles for fear of racial attack because they were considered potential carriers. The Trump administration closed the borders to asylum seekers in order to avoid the spread of Covid-19 in reception facilities and among border guards. Justin Trudeau’s Canada, considered an international symbol of openness and reception for refugees, announced the rejection of asylum seekers attempting to cross the US border illegally.

    The pandemic revived national spirits, in some cases nationalist, even within Europe. The virus confirmed a famous Henry Kissinger metaphor about the fragmented European Union [6]. The well-known American political scientist and Nobel Peace Prize winner wondered, several decades ago, who should I call if I want to talk to Europe? Even today it is difficult to answer this question. Covid-19 called the European switchboard, but there were many voices answering. Some states, including the founding ones such as Germany, formally or actually suspended the free movement of people and goods with the result of slowing down and hampering the transnational transport of medical products and equipment and basic necessities. This political decision penalised everyone, but in particular Italy, the European country that was hit first and more severely than others by the pandemic. In some countries like Italy, the pandemic has also revived forms of territorial selfishness and regional opposition. In Italy there have been cases of conflict between territorial authorities and the State that can be analyzed through internal geopolitics, a discipline that studies the relations between political actors for the control of territories within a State [7]. The State-Region conflicts see the Regional Governors, especially those of a different political color from the government, take positions of opposition to the Government. Unpopular government decisions such as closure of all activities and quarantine at home or complex decisions such as reopenings find strong contrasts between the regional and the state levels. Controversies and accusations over lack of health care facilities, purchase of equipment and organisation of intensive care have shaken public opinion.

    In other European countries the pandemic has increased the level of discrimination and suspicion against immigrants and asylum seekers. For example, in Hungary, Prime Minister Viktor Orban had a coronavirus law passed in Parliament on 30 March. The Hungarian leader could now indefinitely extend the state of emergency without requiring the approval of Members of Parliament. He can suspend certain laws by decree, deviate from statutory regulations and introduce extraordinary measures by order.Viktor Orban justified the temporary rejection of new asylum applications in Hungary on the grounds of fear that immigrants would bring disease. The Greek government, on the other hand, has taken advantage of the health emergency to justify its intention to transform reception centres into closed and supervised facilities increasingly similar to places of detention, and in alarming social and health conditions. The refugee camp on the island of Lesbos, with a capacity of three thousand people, was home, before to be destroyed by fire, to twenty thousand men, women and children, mostly Syrians, who have little or no knowledge of the most basic anti-virus prevention standards. Their condition represents a geopolitical dilemma for Europe. While waiting for the vaccine, do we welcome or refuse refugees seeking asylum in Europe? We are called upon to choose between the legal and moral duty to guarantee security and asylum to those fleeing war and persecution and to protect the health of the host communities by preventing new arrivals from becoming potential, uncontrolled carriers of the virus. Refugees in European reception centres risk becoming an epidemiological time bomb. However, no European country seems interested in facing this geopolitical dilemma. Today refugees, especially Syrians, are, to quote Hannah Arendt, the foam of the earth [8].

    Many states, as we have seen, have tried to assign physical, ethnic and racial specificities to an invisible enemy that instead in its action of contagion acts democratically without distinction of class, age, gender, nationality or religion. This is a typical phenomenon in the history of geopolitics of international health emergencies. New diseases, as the historian William Eamon claims, bring out the deepest phobias in a culture [9]. In these periods people ask for reassurances, politics finds them in unfounded accusations against foreigners. The confirmation of this theory comes from the review, although not exhaustive, of the labels attributed to the pandemics that over the centuries have hit our planet. The bubonic plague, also known as the Jewish plague, broke out in Europe several times. In the mid-14th century, it caused the deaths of millions of people. As the number of victims increased, Christians began to wonder about the origin of that terrible epidemic. Seeing that some Jewish communities had initially saved themselves from contagion, it was decided to blame them: some claimed that they had polluted the wells, others that they wanted to exterminate the Christians by poisoning oil and cheese. So it was that the Jews were struck not only by the plague, but also by the hatred and reprisals of their fellow citizens [10]. Since the 15th century, when syphilis began to spread in Europe, every European country blamed another. And so it became the Neapolitan disease outside Naples, the French disease outside France, the Polish disease in Germany and the German disease in Poland. Then, three centuries later, it became known in Japan as the Portuguese disease and in Persia as the Turkish disease. Long afterwards it was finally understood that, contrary to what was believed, syphilis was not imported by Christopher Columbus from what he believed to be “China”, but that it had already been present in Europe since the time of the ancient Greeks. In some cases, panic and consequent hatred of the alleged transmitters of the disease turned out to be counterproductive in the fight against the disease, as in the late 19th century with a cholera epidemic in the United States. The disease was called the Irish disease because it coincided with the arrival of large flows of migrants from Ireland. In an attempt to contain the contagion, doctors advised people not to drink whiskey, like the Irish men, but water. It was later discovered that the bacterium was proliferating in contaminated well water. It is interesting to note that at the same time, a cholera epidemic in London was the occasion, instead, for the publication of a study that laid the foundations of Health Geography as a scientific discipline. Among the founding studies of this branch of geography is the one conducted in 1854 by the English doctor John Snow on the cholera epidemic in the London district of Soho and, in particular, the Broad Street outbreak. The British luminary, convinced of the close correlation between epidemic and territory, came to the revolutionary conclusion that the main instrument of transmission of cholera was polluted water. To demonstrate the link between cholera incidence and potential geographical sources, i.e. part of the Soho water sources, John Snow was able to elaborate what is now known as the Voronoi diagram. He mapped and circumscribed the districts of the individual water pumps and made boxes representing all the points on his map that were closest to each pump. The section of Snow’s map that indicated the areas of London supplied by the Broad Street water pump corresponded to those in which the greatest number of infected people had been recorded and concentrated. The most skeptical reported that Snow’s theory was falsified by the fact that none of the monks in the only monastery that drew water from the Broad Street water pump had been infected with cholera. It was discovered, however, that this apparent anomaly was due to the fact that the monks preferred to quench their thirst with their own beer rather than water. Similar studies, with the same results, were conducted by Snow’s pupils in the Altona district of Hamburg.

    The English case is, however, an exception in the geopolitics of pandemics, which have always caused an increase in levels of discrimination and suspicion towards foreigners. In fact, the flu plague of 1918–1920 went down in history as the Spanish plague. For the simple reason that in Spain, neutral during the First World War, the press gave news of the pandemic that other European countries preferred to hide in order to appear less weak in the eyes of their opponents. The 1957–1958 flu epidemic is known as Asian because it spread mainly in Asia. Today’s pandemic will probably go down in history as the Chinese virus.

    Despite advances in science and technology, this tendency to still look with distrust at those who are different, and to blame them for our ills, has not changed over time. What has happened in recent weeks will perhaps also explain why we need to choose well which name to give to a new disease, avoiding ethnic or geographical references, but, above all, it has taken us by surprise in the darkness of our old, medieval fears.

    In short, while Covid-19 reaps the benefits of globalization, the governments called upon to combat it adopting national weapons, instruments and categories. In other words, governments use an anachronistic and counterproductive arsenal which, in an era in which space and time are zeroed out in favour of a high mobility, seems to be a thing of the past. It may be for these reasons that in this unprecedented and unpredictable war even the most experienced and refined political leaders have become confused between statements and denials. A rate of general improvisation and disorganization that has few precedents on a global scale.

    It is necessary to elaborate everything that is in place in order to investigate what may be the new instruments and new ways of political organisation to govern this new epochal phase. If, until yesterday, the impact of glocalisation on society and its geopolitical and economic organisation could be considered a recognized fact, the spreading of the virus has made these processes even more evident and tangible, making it essential for the realities that have the task of understanding them and analysing their impacts, to strengthen and update their role. There is no time to lose, at least for those who still want to defend the Western open society. As Yuval Noah Harari wrote, faced with the global threat of Covid-19 we are called to choose between nationalist isolation and global solidarity. Supporters of global solidarity must know that this is not achieved on equal terms, i.e. by simply intensifying relations between nation states. The role of new players must be recognised in helping nation states that have been put in difficulty by glocalisation. For example, the role of the commonwealth and glocal civilizations must be recognized. These are post-national agammaegations that include more identities and more citizenships.

    They are transnational networks that interconnect continents, territories with increasingly porous borders, sub-national and local actors. They are confirmation of how, as Parag Khanna has already pointed out, megalopolises and regional groupings will increasingly assume power. While national governments and traditional global multilateral organisations will struggle to cope with this rapid dispersion of power [11], such a new international institutional horizon would be a kind of multiscale weapon to respond, at the same time, to global and local challenges. It is this glocal approach that the scientific community seems to be following these days, while politics and the economy turns towards closure and statism, a phenomenon that Slavoj Zizek has defined with a neologism the communism of disasters [12].

    In fact, a scientific-technological campaign unprecedented in human history is underway. United twenty-four hours a day by social media, despite the different time zones, doctors, microbiologists, biologists, data scientists, network experts, communicate with tools unknown to their colleagues in the 2000s, at the time of the Sars epidemic. The difference with the pandemics of the past is in the enormous amount of data available today, produced in recent months. Scientists have come out of their labs, put the progress made online in real time, allowing distant research institutes to assimilate and corroborate them. At the request of the President of the United States, enlightened by Prof. Anthony Fauci, an Italian-American virologist already a pioneer in the fight against AIDS, the Office of Science and Technology Policy (OSTP) created in a few weeks a constantly updated database on Covid-19. To this purpose the National Library of Medicine has listed the scientific publications, Microsoft has engaged the algorithms by collating the most important entries, the Allen Institute for Artificial Intelligence has changed them from web pages and pdf into texts readable by the various algorithms. The OSTP now wants to use Artificial Intelligence against the virus, splitting complex problems into small tasks and letting the masses of collaborators solve them. Thousands of dollars are awarded to developers who are the first to find the solution to a given unknown in every part of the globe. These are examples that seem to indicate that the international scientific community has already chosen the path of global solidarity with a glocal approach rather than nationalist isolation. It remains to be seen whether politics will follow the same path. If not, the scenario of a potential world conflict between nation-states could go beyond the perimeter of the conspiracy narrative and fall on our daily lives.

    It seems, in fact, that the Covid-19 pandemic has accelerated the clash between the United States and China for dominance on the global chessboard. From 1945 to 1991, the world was in balance between the United States and the Soviet Union. From 1991 to 1999–2000 and the rise to power of Vladimir Putin, there was a kind of interregnum during which the West believed in the end of history and its final triumph. Since Donald Trump became President of the United States in 2016, a triple understanding has been established globally: the American monopoly (strategic and financial), the Chinese giant’s hyperpower (mainly economic) and the Russian superpower (military and geographical). The rest of the West has discovered that there are only empires or embryos of empire on the planet that decide according to their own interests. The fundamental pillar of the international order on which the balance of the world seen by Westerners rested, the Atlantic Alliance, seems to be in crisis. For the Americans, and the process has accelerated with the start of the pandemic, Europe is no longer an ally but a pawn on the chessboard in their fight against China. They confront their former allies with a request for an agreement: the defence of Europe against the shared containment of Chinese influence. A scenario confirmed by American policy during the pandemic: the brutal closure of the borders to Europeans denounced as carriers of the virus; the takeover bid for the CureVac laboratory, German developer of the coronavirus vaccine; possible priority treatment for Americans in case Sanofi collaborates with the Biomedical Advanced Research and Development Authority (Barda) on vaccines. Even in the Western Balkans, the action of the United States no longer coincides with that of Europeans. For example in Kosovo, Washington contributed to the fall of the government of Albin Kurti (left-wing nationalist anti-corruption party), in power for two months, supported by Brussels, as this established the conditions for rapprochement with Serbia [13].

    For its part, China knows that it bears a major responsibility for the spread of the new zoonosis—as previously with Sars (severe acute respiratory syndrome, 2002–2004) and H5N1 avian influenza (2003–2004). At least two legal hypotheses have been taken into consideration by the US Senators from Missouri, Mississippi, Tennessee, Arkansas, South Carolina who want to punish the Chinese: (1) to eliminate part of the debt contracted by the US Treasury held by China or to cancel the repayment of the maturing securities and/or not to pay interest (equivalent on average to 1.2%) on the 1100 billion dollars in US Bonds held by the Chinese; (2) to disengage the US and Chinese economies by law by requiring the US multinationals to withdraw from China.

    China claims instead that the pandemic was caused by the United States and in general spread by Western States. According to Beijing, the pandemic started in the laboratory of Fort Detrick (Maryland) in 2019 and it was the American soldiers who spread the virus in Wuhan during the Ⅶ World Military Games last October. In France, the Chinese Embassy accuses on its website the incompetence of medical staff employed in nursing homes for the elderly. In Sweden, Chinese denials of the origin of the virus were not welcomed and the last Confucius Institute was closed down to obstruct its propaganda. In Germany, the Ministry of the Interior confirms that the government has not reacted to Chinese requests to enhance Beijing’s role.

    In Australia, Ambassador Cheng Jingye threatens the country with a boycott (Australian wine and beef of which China is the main importer), student withdrawal and cancellation of tourism, if Canberra continues to call for an international and independent commission of inquiry into the pandemic, the Wuhan episode and the role of the WHO. This, however, risks causing immense damage to the gigantic Belt and Roads Initiative project wanted by President Xi Jinping to restore the centrality of popular China in the world.

    In this potential clash between the American and Chinese empires, the United States is at a disadvantage for three reasons.

    The first is geopolitical. In the face of the monolithicism of the Beijing regime, in the US and the rest of the West there is an internal clash within our civilization. The western geopolitical chessboard is divided and fragmented by the confrontation between two political sides that have divergent worldviews: national, if not nationalist, isolationists, led by Donald Trump and supported in Europe by Great Britain, which has just left the EU, are confronted by the line-up of the multilateralist-globalists without leadership. With the rediscovered special relationship between the US and Great Britain, the Anglo-Americans, as they were called at the time of the Second World War, seem once again to have gone to war: this time, however, not to defend the attacked democracy, but to move from the defence of democracy to the defence from democracy, from the imposition of economic globalisation to the fight against it. The result is that today the main defender of globalization, political and economic, is the People’s Republic of China with its communist capitalism.

    The second is geoeconomic. The current pandemic threatens Western capitalism and strengthens communist capitalism. In order to prevent the health crisis from resulting in a long economic depression, a greater and prolonged role for the state in the American industrial scenario will also be needed. The free hand of the market, a pillar of made in US may not be enough this time to boost American GDP. Many companies will be forced to downsize and automate themselves to make a profit while producing much less: so the US could also have high unemployment rates. We will need forms of universal income, protection for the workers of the gig economy, social safety nets, i.e. a massive redistribution of wealth that only the State can manage. Beijing seems to have an advantage also on this front.

    The third is cultural. It will take more than a year to get and administer a Covid-19 vaccine to the world population. We will be forced into a long period of living with the invisible enemy. In order to avoid new outbreaks of contagion and consequent lockdown (our houses are the new ghettos reminiscent of Venetian ghettos), timely and urgent state interventions will be needed. Citizens will need loyalty, empathy, reliability, sense of community, respect and trust in the authorities. Characteristics that seem more traceable in the Confucian ethics characteristic of Beijing’s communist capitalism than in the capitalist spirit of Weberian memory typical of Anglo-American individualistic culture.

    In this war between giants, the divided and fragmented Europe risks becoming a battleground between the two contenders. A scenario that particularly concerns the states of Mediterranean Europe due to fragile economic and political systems. Think, for example, of the international aids received by Italy in the most acute phase of the health emergency. Albania, China, Cuba, Russia, anticipated Italy’s traditional international allies by sending medical products and personnel. While the western bloc, from Europe to the US, was divided on whether and how to support Rome, the states of the former communist bloc were already active and operative on Italian territory. The image of military doctors, including perhaps top secret services executives, and Russian-flagged trucks moving around the territory of a member State of Nato like Italy, is perhaps only an anticipation of the upcoming geopolitical scenarios. At the same time a team of Chinese doctors arrived from Beijing, with related medical devices, worked side by side with their Italian counterparts at Spallanzani Hospital, a strategic social-healthcare structure of excellence, from which they may have learned valuable know-how at home. An action of soft power, that of the countries of the former communist bloc, which has helped to change the popular perception of traditional alliances in Italy. According to a Swg survey conducted between March 20 and April 12, under the category of countries friendly to Italy first place went to China, the second to Russia and only third to the US, while among the enemies Germany, France and Great Britain stood out in order. This data confirms in particular the success of the so-called mask diplomacy of the Chinese government. In fact, at the beginning of the current health emergency in Italy (and not only) the disease carriers were considered the Chinese and the contagions were exclusively related to Chinese people. But China, with an action of soft power (donations of devices and medical personnel) have managed, as we have seen, to rise higher in the Italian sympathies.

    In the clash with China, the US, we have said, is at a disadvantage, but its defeat is not a foregone conclusion. The lack of transparency in the People’s Republic of China does not allow us to have an account of the real causes and consequences of Covid-19 on the Chinese economic, political and social fabric. In the medium to long term, the Chinese government could be forced to face problems of internal political stability: competition for public resources between the administrations of urban and rural areas; conflicts between state capitalists and the working class due to the increase in labour costs; public investment to raise the quality of social welfare services and health and hygiene standards which, unlike large cities, in China’s vast internal areas, have modest levels.

    The outcome of the confrontation between Beijing and Washington is therefore uncertain. Uncertainty will govern the world in the coming years. Both China and the United States cannot rely on a consolidated system of international alliances. Unlike the first Cold War, there are no two compact blocks that oppose each other. We have entered the G-Zero world, a neologism coined by American political scientist Ian Bremmer [14]. According to Bremmer, the G-20 will be replaced by the G-Zero. Many states will be involved in several regional conflicts, but for the first time in seventy years there will not be a single power or alliance of powers able to assume global leadership.The absence of global dominus leads governments around the world to stand up as guardians of national social and economic security to address the unresolved and developing medical issues, economic issues and the pressures of people who want their personal freedoms back.

    The international health emergency seems to have accelerated the beginning of a new glocal era [15], based on a close correlation between the local and the global sphere. The international scientific community has already chosen the path of global solidarity with a glocal approach rather than nationalist isolation. Instead, the perception that the risks caused by the spread of the virus could undermine national security and sovereignty has led most states to isolate themselves by refraining from multilateral cooperation. We are witnessing a clash between the United States and China for dominance on the global chessboard. It will have to be seen whether this confrontation will produce a new world order based on global solidarity with a glocal approach or based on national isolation, with many regional powers and no major international powers.

    I declare no conflict of interest on this manuscript.



    [1] Iwata Y, Sugimoto H, Kuwamura H (2006) Reparability limit of steel buildings based on the actual data of the Hyogoken-Nanbu earthquake, Proceedings of the 38th Joint Panel. Wind and Seismic effects, NIST Special Publication, 1057: 23-32.
    [2] McCormick J, Aburano H, Ikenaga M, et al. (2008) Permissible residual deformation levels for building structures considering both safety and human elements, Proceedings of the 14th world conference on earthquake engineering, China: Seismological Press Beijing, 12-17.
    [3] Kasai K, Fu Y, Watanabe A (1998) Passive control systems for seismic damage mitigation. J Struct Eng 124: 501-512. https://doi.org/10.1061/(ASCE)0733-9445(1998)124:5(501) doi: 10.1061/(ASCE)0733-9445(1998)124:5(501)
    [4] Black CJ, Makris N, Aiken ID (2002) Component testing, stability analysis and characterization of buckling-restrained braces. PEER 2002/08, Pacific Earthquake Engineering Research Center, University of California, Berkeley.
    [5] Fahnestock LA, Sause R, Ricles JM, et al. (2003) Ductility demands on buckling restrained braced frames under earthquake loading. Earthq Eng Eng Vib 2: 255-268. https://doi.org/10.1007/s11803-003-0009-5 doi: 10.1007/s11803-003-0009-5
    [6] Sabelli R, Mahin S, Chang C (2003) Seismic demands on steel braced frame buildings with buckling-restrained braces. Eng Struct 25: 655-666. https://doi.org/10.1016/S0141-0296(02)00175-X doi: 10.1016/S0141-0296(02)00175-X
    [7] Newell J, Uang CM, Benzoni G (2006) Subassemblage testing of core brace buckling restrained braces (G Series). TR-06/01, University of California, San Diego.
    [8] Tremblay R, Bolduc P, Neville R, et al. (2006) Seismic testing and performance of buckling restrained bracing systems. Can J Civil Eng 33: 183-198. https://doi.org/10.1139/l05-103 doi: 10.1139/l05-103
    [9] Naghavi M, Rahnavard R, Robert J (2019) Numerical evaluation of the hysteretic behavior of concentrically braced frames and buckling restrained brace frame systems. J Build Eng 22: 415-428. https://doi.org/10.1016/j.jobe.2018.12.023 doi: 10.1016/j.jobe.2018.12.023
    [10] MacRae G, Kimura Y, Roeder C (2004) Effect of column stiffness on braced frame seismic behavior. J Struct Eng 130: 381-391. https://doi.org/10.1061/(ASCE)0733-9445(2004)130:3(381) doi: 10.1061/(ASCE)0733-9445(2004)130:3(381)
    [11] Zaruma S, Fahnestock LA (2018) Assessment of design parameters influencing seismic collapse performance of buckling restrained braced frames. Soil Dyn Earthq Eng 113: 35-46. https://doi.org/10.1016/j.soildyn.2018.05.021 doi: 10.1016/j.soildyn.2018.05.021
    [12] Kiggins S, Uang CM (2006) Reducing residual drift of buckling-restrained braced frames as a dual system. Eng Struct 28: 1525-1532. https://doi.org/10.1016/j.engstruct.2005.10.023 doi: 10.1016/j.engstruct.2005.10.023
    [13] Erochko J, Christopoulos C, Tremblay R, et al. (2011) Residual drift response of SMRFs and BRB Frames in steel buildings designed according to ASCE 7-05. J Struct Eng 137: 589-599. https://doi.org/10.1061/(ASCE)ST.1943-541X.0000296 doi: 10.1061/(ASCE)ST.1943-541X.0000296
    [14] Ariyaratana CA, Fahnestock LA (2011) Evaluation of buckling-restrained braced frame seismic performance considering reserve strength. Eng Struct 33: 77-89. https://doi.org/10.1016/j.engstruct.2010.09.020 doi: 10.1016/j.engstruct.2010.09.020
    [15] Hoveidae N, Tremblay R, Rafezy B, et al. (2015) Numerical investigation of seismic behavior of short-core all-steel buckling restrained braces. J Constr Steel Res 114: 89-99. https://doi.org/10.1016/j.jcsr.2015.06.005 doi: 10.1016/j.jcsr.2015.06.005
    [16] Pandikkadavath M, Sahoo DR (2016) Analytical investigation on cyclic response of buckling-restrained braces with short yielding core segments. Int J Steel Struct 16: 1273-1285. https://doi.org/10.1007/s13296-016-0083-y doi: 10.1007/s13296-016-0083-y
    [17] Hoveidae N, Radpour S (2021) A novel all-steel buckling restrained brace for seismic drift mitigation of steel frames. B Earthq Eng 19: 1537-1567. https://doi.org/10.1007/s10518-020-01038-0 doi: 10.1007/s10518-020-01038-0
    [18] Mazzolani F (2008) Innovative metal systems for seismic upgrading of RC structures. J Constr Steel Res 64: 882-895. https://doi.org/10.1016/j.jcsr.2007.12.017 doi: 10.1016/j.jcsr.2007.12.017
    [19] Yooprasertchai E, Warnitchai P (2008) Seismic retrofitting of low-rise nonductile reinforced concrete buildings by buckling-restrained braces, Proceedings of 14th World Conference on Earthquake Engineering, Beijing.
    [20] Dinu F, Bordea S, Dubina D (2011) Strengthening of non-seismic reinforced concrete frames of buckling restrained steel braces, Behaviour of Steel Structures in Seismic Areas, 1 Ed., CRC Press.
    [21] Mahrenholtz C, Lin P, Wu A, et al. (2015) Retrofit of reinforced concrete frames with buckling-restrained braces. Earthqu Eng Struct D 44: 59-78. https://doi.org/10.1002/eqe.2458 doi: 10.1002/eqe.2458
    [22] Abou-Elfath H, Ramadan M, Alkanai FO (2017) Upgrading the seismic capacity of existing RC buildings using buckling restrained braces. Alex Eng J 56: 251-262. https://doi.org/10.1016/j.aej.2016.11.018 doi: 10.1016/j.aej.2016.11.018
    [23] Ozcelik R, Erdil EE (2019) Pseudodynamic test of a deficient RC frame strengthened with buckling restrained braces. Earthqu Spectra 35: 1163-1187. https://doi.org/10.1193/122317EQS263M doi: 10.1193/122317EQS263M
    [24] Al-Sadoon ZA, Saatcioglu M, Palermo D (2020) New buckling-restrained brace for seismically deficient reinforced concrete frames. J Struct Eng 146: 04020082. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002439 doi: 10.1061/(ASCE)ST.1943-541X.0002439
    [25] Sutcu F, Bal A, Fujishita K, et al. (2020) Experimental and analytical studies of sub‑standard RC frames retrofitted with buckling‑restrained braces and steel frames. B Earthq Eng 18: 2389-2410. https://doi.org/10.1007/s10518-020-00785-4 doi: 10.1007/s10518-020-00785-4
    [26] Castaldo P, Tubaldi E, Selvi F, et al. (2021) Seismic performance of an existing RC structure retrofitted with buckling restrained braces. J Build Eng 33: 101688. https://doi.org/10.1016/j.jobe.2020.101688 doi: 10.1016/j.jobe.2020.101688
    [27] Xu ZD, Shen YP, Guo YQ (2003) Semi-active control of structures incorporated with magnetorheological dampers using neural networks. Smart Mater Struct 12: 80-87. https://doi.org/10.1088/0964-1726/12/1/309 doi: 10.1088/0964-1726/12/1/309
    [28] Dai J, Xu ZD, Gai PP, et al. (2021) Optimal design of tuned mass damper inerter with a Maxwell element for mitigating the vortex-induced vibration in bridges. Mech Syst Signal Pr 148: 107180. https://doi.org/10.1016/j.ymssp.2020.107180 doi: 10.1016/j.ymssp.2020.107180
    [29] American Institute of Steel Construction (AISC) (2016) Seismic provisions for structural steel buildings. ANSI/AISC 341-16.
    [30] Dehghani M, Tremblay R (2012) Development of standard dynamic loading protocol for buckling-restrained braced frames. International Specialty Conference on Behaviour of Steel Structures in Seismic Area (STESSA 2012), Santiago de Chile
    [31] Razavi, SA, Mirghaderi, SR, Seini, A, et al. (2012) Reduced length buckling restrained brace using steel plates as restraining segment, Proceedings of the 15th World Conference on Earthquake Engineering, Lisbon, Portugal.
    [32] Nakamura H, Maeda Y, Sasaki T, et al. (2000) Fatigue properties of practical-scale unbonded braces. Nippon Steel Tech Rep 82: 51-57.
    [33] Miner MA (1945) Cumulative damage in fatigue. J Appl Mech 12: 159-164. https://doi.org/10.1115/1.4009458 doi: 10.1115/1.4009458
    [34] Usami T, Wang C, Funayama J (2011) Low-cycle fatigue tests of a type of buckling restrained braces. Procedia Eng 14: 956-964. https://doi.org/10.1016/j.proeng.2011.07.120 doi: 10.1016/j.proeng.2011.07.120
    [35] Tabatabaei SAR, Mirghaderi SR, Hosseini A (2014) Experimental and numerical developing of reduced length buckling-restrained braces. Eng Struct 77: 143-160. https://doi.org/10.1016/j.engstruct.2014.07.034 doi: 10.1016/j.engstruct.2014.07.034
    [36] Pandikkadavath MS, Sahoo DR (2020) Development and subassemblage cyclic testing of hybrid buckling-restrained steel braces. Earthq Eng Eng Vib 19: 967-983. https://doi.org/10.1007/s11803-020-0607-5 doi: 10.1007/s11803-020-0607-5
    [37] Sabelli R (2001) Research on Improving the Design and Analysis of Earthquake-Resistant Steel Braced Frames, California: Earthquake Engineering Research Institute.
    [38] SeismoStruct, 2022. A computer program for static and dynamic nonlinear analysis of framed structures. Available from: http://www.seismosoft.com/SeismoStruct.
    [39] Mander JB, Priestley MJN, Park R (1988) Theoretical stress-strain model for confined concrete. J Struct Eng 114: 1804-1826. https://doi.org/10.1061/(ASCE)0733-9445(1988)114:8(1804) doi: 10.1061/(ASCE)0733-9445(1988)114:8(1804)
    [40] Martinez-Rueda JE, Elnashai AS (1997) Confined concrete model under cyclic load. Mater Struct 30: 139-147. https://doi.org/10.1007/BF02486385 doi: 10.1007/BF02486385
    [41] American Concrete Institute (ACI) Committee 318 (2019) Building code requirements for structural concrete. ACI 318-19.
    [42] International code council (2018) 2018 International Building Code. Available from: https://codes.iccsafe.org/content/IBC2018/copyright.
    [43] Kiggins K, Uang CM (2006) Reducing residual drift of buckling-restrained braced frames as a dual system. Eng Struct 28: 1525-1532. https://doi.org/10.1016/j.engstruct.2005.10.023
    [44] Kiggins K and Uang CM (2006) Reducing residual drift of buckling-restrained braced frames as a dual system. Eng Struct 28: 1525-1532. https://doi.org/10.1016/j.engstruct.2005.10.023 doi: 10.1016/j.engstruct.2005.10.023
    [45] Vamvatsikos D, Cornell CA (2004) Applied incremental dynamic analysis. Earthq Spectra 20: 523-553. https://doi.org/10.1193/1.1737737 doi: 10.1193/1.1737737
    [46] Kitayama S, Constantinou MC (2018) Collapse performance of seismically isolated buildings designed by the procedures of ASCE/SEI 7. Eng Struct 164: 243-258. https://doi.org/10.1016/j.engstruct.2018.03.008 doi: 10.1016/j.engstruct.2018.03.008
    [47] Kitayama S, Constantinou MC (2019) Probabilistic seismic performance assessment of seismically isolated buildings designed by the procedures of ASCE/SEI 7 and other enhanced criteria. Eng Struct 179: 566-582. https://doi.org/10.1016/j.engstruct.2018.11.014 doi: 10.1016/j.engstruct.2018.11.014
    [48] Castaldo P, Amendola G (2021) Optimal DCFP bearing properties and seismic performance assessment in nondimensional form for isolated bridges. Earthq Eng Struct D 50: 2442-2461. https://doi.org/10.1002/eqe.3454 doi: 10.1002/eqe.3454
    [49] Castaldo P, Amendola G (2021) Optimal sliding friction coefficients for isolated viaducts and bridges: A comparison study. Struct Control Hlth e2838. https://doi.org/10.1002/stc.2838
    [50] Applied Technology Council (2009) Quantification of Building Seismic Performance Factors, Washington: Federal Emergency Management Agency.
    [51] Federal Emergency Management Agency (2000) Prestandard and Commentary for the Seismic Rehabilitation of Buildings, FEMA 356, Washington, DC, USA.
  • This article has been cited by:

    1. Aziz Belmiloudi, Brain Connectivity Dynamics and Mittag–Leffler Synchronization in Asymmetric Complex Networks for a Class of Coupled Nonlinear Fractional-Order Memristive Neural Network System with Coupling Boundary Conditions, 2024, 13, 2075-1680, 440, 10.3390/axioms13070440
    2. Li Cai, Jin Cao, Feifei Jing, Yongheng Wang, A fast time integral finite difference method for a space-time fractional FitzHugh-Nagumo monodomain model in irregular domains, 2024, 501, 00219991, 112744, 10.1016/j.jcp.2023.112744
    3. Soveny Solís, Vicente Vergara, Non-existence of Solutions for a Non-Gaussian Equation in Fractional Time with Osgood Type Non-linearity, 2025, 1040-7294, 10.1007/s10884-025-10411-z
    4. M. Krasnoschok, Classical solutions of time-fractional quasilinear reaction-diffusion systems, 2025, 77, 1027-3190, 123, 10.3842/umzh.v77i2.1147
    5. Ricardo Almeida, Euler–Lagrange type equations involving fractional derivatives with arbitrary kernels and dependence on the initial point, 2025, 0, 2164-6066, 0, 10.3934/jdg.2025006
  • Reader Comments
  • © 2022 the Author(s), licensee AIMS Press. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0)
通讯作者: 陈斌, bchen63@163.com
  • 1. 

    沈阳化工大学材料科学与工程学院 沈阳 110142

  1. 本站搜索
  2. 百度学术搜索
  3. 万方数据库搜索
  4. CNKI搜索

Metrics

Article views(3980) PDF downloads(208) Cited by(0)

Other Articles By Authors

/

DownLoad:  Full-Size Img  PowerPoint
Return
Return

Catalog