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带支撑黏弹性阻尼器框架减震性能分析
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作者 张敏 庞华英 《应用力学学报》 CAS CSCD 北大核心 2020年第1期418-426,I0029,I0030,共11页
对带有支撑黏弹性阻尼器耗能框架结构振动方程进行傅里叶变换,求解该振动方程的频域解,再通过傅里叶逆变换得出该方程的时域解,由此研究了阻尼器的支撑系数y、松弛时间系数h对结构地震响应的影响,分析了带支撑黏弹性阻尼器在结构各楼层... 对带有支撑黏弹性阻尼器耗能框架结构振动方程进行傅里叶变换,求解该振动方程的频域解,再通过傅里叶逆变换得出该方程的时域解,由此研究了阻尼器的支撑系数y、松弛时间系数h对结构地震响应的影响,分析了带支撑黏弹性阻尼器在结构各楼层均匀布置时结构的地震作用及结构各振型的底部剪力。结果表明:支撑系数y超过一定数值时,阻尼器支撑对结构的地震反应影响很小;框架结构中带支撑的黏弹性阻尼器宜合理控制松弛时间系数h,使其不大于0.5。 展开更多
关键词 框架 黏弹性 阻尼器 频域 支撑 松弛时间系数 傅里叶变换 傅里叶逆变换
皮肤黏弹性的体内检测方法研究现状与展望 预览
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作者 陆思宇 曲晓威 +1 位作者 张彤 宋义林 《北京生物医学工程》 2020年第1期96-102,共7页
皮肤黏弹性作为皮肤组织的重要生物力学特性,对生理病理状态的分析、诊断、治疗有着极其重要的参考价值和指导作用,是评价皮肤功能的重要指标。近年来,随着生活水平的日渐提高和家庭护理需求的不断提升,人们越来越重视皮肤的美容、保健... 皮肤黏弹性作为皮肤组织的重要生物力学特性,对生理病理状态的分析、诊断、治疗有着极其重要的参考价值和指导作用,是评价皮肤功能的重要指标。近年来,随着生活水平的日渐提高和家庭护理需求的不断提升,人们越来越重视皮肤的美容、保健与护理。因此,与人体皮肤黏弹性相关的体内检测方法得到了广泛关注,皮肤黏弹性体内检测装置的研发也有了进一步推进。本文阐述了各类皮肤黏弹性体内检测方法的原理与技术发展历程,归纳了各种检测方法的优缺点并做了对比分析,最后对皮肤黏弹性未来的研究方向进行了展望。 展开更多
关键词 皮肤 黏弹性 检测方法 印压法 生物力学
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The role of viscoelastic damping on retrofitting seismic performance of asymmetric reinforced concrete structures 预览
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作者 Zeshan Alam Chunwei Zhang Bijan Samali 《地震工程与工程振动:英文版》 SCIE EI CSCD 2020年第1期223-237,共15页
The primary purpose of this research is to improve the seismic response of a complex asymmetric tall structure using viscoelastic(VE) dampers. Asymmetric structures have detrimental effects on the seismic performance ... The primary purpose of this research is to improve the seismic response of a complex asymmetric tall structure using viscoelastic(VE) dampers. Asymmetric structures have detrimental effects on the seismic performance because such structures create abrupt changes in the stiffness or strength that may lead to undesirable stress concentrations at weak locations. Structural control devices are one of the effective ways to reduce seismic impacts, particularly in asymmetric structures. For passive vibration control of structures, VE dampers are considered among the most preferred devices for energy dissipation. Therefore, in this research, VE dampers are implemented at strategic locations in a realistic case study structure to increase the level of distributed damping without occupying significant architectural space and reducing earthquake vibrations in terms of story displacements(drifts) and other design forces. It has been concluded that the seismic response of the considered structure retrofitted with supplemental VE dampers corresponded well in controlling the displacement demands. Moreover, it has been demonstrated that seismic response in terms of interstory drifts was effectively mitigated with supplemental damping when added up to a certain level. Exceeding the supplemental damping from this level did not contribute to additional mitigation of the seismic response of the considered structure. In addition, it was found that the supplemental damping increased the total acceleration of the considered structure at all floor levels, which indicates that for irregular tall structures of this type, VE dampers were only a good retrofitting measure for earthquake induced interstory deformations and their use may not be suitable for acceleration sensitive structures. Overall, the research findings demonstrate how seismic hazards to these types of structures can be reduced by introducing additional damping into the structure. 展开更多
关键词 VISCOELASTIC DAMPERS SEISMIC ANALYSIS ASYMMETRIC structure nonlinear MODAL time history ANALYSIS
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任意荷载下连续排水边界分数阶黏弹性地基一维固结模型 预览
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作者 王珏 童立红 +1 位作者 金立 徐长节 《土木与环境工程学报(中英文)》 CSCD 北大核心 2020年第1期56-63,共8页
以基于Caputo分数阶导数的弹壶元件修正Kelvin模型来描述饱和土体一维固结的力学行为,并引入连续排水边界条件,通过Laplace变换,联立求解得到任意荷载下连续排水边界分数阶黏弹性地基有效应力及固结沉降的解析解。采用Laplace逆变换,获... 以基于Caputo分数阶导数的弹壶元件修正Kelvin模型来描述饱和土体一维固结的力学行为,并引入连续排水边界条件,通过Laplace变换,联立求解得到任意荷载下连续排水边界分数阶黏弹性地基有效应力及固结沉降的解析解。采用Laplace逆变换,获得了其时域内的理论解,并分析了梯形循环荷载及施工荷载作用下相关参数对固结沉降的影响。研究结果表明:循环荷载作用下,黏土地基的沉降变化呈振荡增长,且振荡幅值随着边界透水性的增大而增大;分数阶次α增大,使固结前期沉降速率减慢,而在固结后期,α值对沉降的影响正好相反;循环荷载下沉降变化曲线的振荡幅值随着分数阶次α的增大而减小。此外,一维固结沉降的发展还与土体力学参数及荷载参数相关,弹性模量E越大,最终沉降量越小;黏弹性体的延迟时间F越大,固结沉降变化越慢。 展开更多
关键词 任意荷载 连续排水边界 分数阶导数 黏弹性 一维固结
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汽车多楔带摩擦噪声机理分析与试验研究 预览
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作者 唐武生 宁凯 +1 位作者 史尧臣 于雪莲 《机械传动》 北大核心 2020年第1期122-124,149共4页
针对汽车多楔带传动时噪声的特性与变化规律,通过分析多楔带噪声产生的机理,建立了摩擦振动的理论模型,推导出多楔带传动系统的不稳定条件,并在设计的振动和噪声测试试验台上进行了多楔带传动振动和噪声试验研究。结果表明,带段张力的... 针对汽车多楔带传动时噪声的特性与变化规律,通过分析多楔带噪声产生的机理,建立了摩擦振动的理论模型,推导出多楔带传动系统的不稳定条件,并在设计的振动和噪声测试试验台上进行了多楔带传动振动和噪声试验研究。结果表明,带段张力的波动导致了多楔带的低频振动噪声,带与带轮间的黏滑摩擦引起了高频摩擦噪声。 展开更多
关键词 摩擦 黏滑 噪声 振动
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Identifying the viscoelastic properties of soft matter from the indentation response of a hard film-soft substrate system
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作者 YanWei Liu YueGuang Wei and Hao Long 《中国科学:物理学、力学、天文学英文版》 SCIE EI CAS CSCD 2020年第4期108-118,共11页
The indentation technique is widely used in measuring the mechanical properties of soft matter at the microscale or nanoscale,but still faces challenges by these unique properties as well as the consequent strong surf... The indentation technique is widely used in measuring the mechanical properties of soft matter at the microscale or nanoscale,but still faces challenges by these unique properties as well as the consequent strong surface adhesion, including the strong nonlinear effect, unclear judgment of the contact point, difficulties in estimating the contact area, and the risk of the indenter piercing the sample. Here we propose a two-step method to solve these problems: lay a hard film on a soft matter, and obtain the viscoelastic properties of this soft matter through the indentation response of this composite structure. We first establish a theoretical indentation model of the hard film-soft substrate system based on the theory of plates, elastic-viscoelastic correspondence principle and Boltzmann superposition principle. To verify the correctness of this method, we measure the mechanical properties of the methyl vinyl silicone rubber(MVSR) covered by a Cu nanofilm. Finally, we test the effectiveness and error sensitivity of this method with the finite element method(FEM). The results show that our method can accurately measure the mechanical properties of soft matter, while effectively circumventing the problems of the traditional indentation technique. 展开更多
关键词 viscoelastic properties soft matter theoretical indentation model indentation technique finite element method
Viscoelastic Evaluation of Different Hyaluronic Acid Based Fillers Using Vibrational Optical Coherence Tomography 预览
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作者 Frederick H. Silver Ruchit G. Shah +3 位作者 Nikita Kelkar Dominick Benedetto Dale DeVore Justin Cohen 《材料科学与应用期刊(英文)》 2019年第5期423-431,共9页
Hylauronic acid (HA) is used as a viscoelastic in Ophthalmology during cataract surgery based on its high viscosity at rest, its ability to shear thin and dissipate energy during phacoemulsification. However, these pr... Hylauronic acid (HA) is used as a viscoelastic in Ophthalmology during cataract surgery based on its high viscosity at rest, its ability to shear thin and dissipate energy during phacoemulsification. However, these properties of HA solutions would make them susceptible to migration when used as dermal filler materials. In this study, we apply a new technique termed vibrational optical coherence tomography (VOCT) to compare the physical properties of different HA solutions and fillers used in facial aesthetics. Results presented in this study suggest that HA solutions and HA dermal fillers have markedly different physical properties. HA solutions are highly viscoelastic with high % viscous losses while fillers tend to have lower viscous energy dissipation properties. Clinical observations suggest that the high loss fillers are injected more superficially in the face where tension and internal and external forces are more likely minimized giving tissue of the hands and lips more volume and allowing more natural movement. In contrast, the lower loss gels that are used to lift tissue, generally have a higher G’, and are injected deeper into the face where injection and internal forces are likely to be higher. It is concluded that HA filler gel design can be optimized by use of VOCT to evaluate the % viscous energy loss both in vitro and in vivo. 展开更多
关键词 Hyaluronic Acid Injectable FILLER Dermal FILLER Plastic SURGERY Cosmetic SURGERY VISCOELASTIC Mechanical Properties Facial SURGERY Optical COHERENCE TOMOGRAPHY VIBRATIONAL Optical COHERENCE TOMOGRAPHY
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Proposal to Study Uniqueness Problem of Rayleigh Wave in Half-Space Kelvin Viscoelastic Media 预览
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作者 Hua Cheng Takashi Takiguchi 《应用数学与应用物理(英文)》 2019年第9期2074-2088,共15页
Rayleigh wave is an interference wave of longitudinal wave and transverse wave which propagate along the free surface of solids. There remains a dispute about the number of Rayleigh waves in viscoelastic media until n... Rayleigh wave is an interference wave of longitudinal wave and transverse wave which propagate along the free surface of solids. There remains a dispute about the number of Rayleigh waves in viscoelastic media until now, which is an essential problem of Rayleigh wave propagation. The purpose of this study is to propose a brief way of handling this essential problem within half-space Kelvin viscoelastic media. Starting from the dynamic equations of transverse wave and longitudinal wave based on Kelvin viscoelastic model, this study sets the complex wave number as a variable, introduces complex moduli and complex exponential factors, then a characteristic equation of Kelvin viscoelastic Rayleigh wave in half space is derived and simplified support for analysis of its uniqueness. After reviewing mathematical models describing phenomena of having multiple solutions but uniqueness when a natural condition is taken into account, a conjecture is given that the Rayleigh wave in Kelvin viscoelastic media must be unique if we assume a natural condition in accordance with the natural phenomena. 展开更多
关键词 Rayleigh WAVE VISCOELASTIC WAVE EQUATION Characteristic EQUATION KELVIN Model
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海洋柔性管道用复合材料的粘弹性研究 预览
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作者 黄允灿 韩霞 《船电技术》 2019年第12期24-28,共5页
本文主要研究了柔性管道的结构中起增强作用的增强层材料在长期载荷下的蠕变行为。文中用连续拉挤成型工艺制备了CGFRPP单层板,利用万能力学试验机和DMA测试仪测得了预测模型和理论所需要的力学数据,根据所测得的力学数据分别用Burgers... 本文主要研究了柔性管道的结构中起增强作用的增强层材料在长期载荷下的蠕变行为。文中用连续拉挤成型工艺制备了CGFRPP单层板,利用万能力学试验机和DMA测试仪测得了预测模型和理论所需要的力学数据,根据所测得的力学数据分别用Burgers模型和时间-温度-应力等效原理(TTSSP)预测CGFRPP的长期力学性能,并将两种预测方法所得的结果进行了分析和比较。研究表明TTSSP对CGFRPP复合材料低应力下的蠕变行为预测具有较好的适用性,Burgers粘弹性模型对于CGFRPP复合材料的蠕变行为预测具有良好的适用性。 展开更多
关键词 柔性管道 复合材料 粘弹性
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Direct numerical simulation of the viscoelastic channel flow using Giesekus model with variable parameters 预览
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作者 Wei-guo Gu Yu Li De-zhong Wang 《水动力学研究与进展:英文版》 SCIE EI CSCD 2019年第2期326-332,共7页
The paper presents a direct numerical simulation(DNS)for the drag-reducing channel flow using the Giesekus model with variable parameters.It is assumed that the relaxation time in the constitutive equation is varied d... The paper presents a direct numerical simulation(DNS)for the drag-reducing channel flow using the Giesekus model with variable parameters.It is assumed that the relaxation time in the constitutive equation is varied depending on the local shear rate.The maximal drag reduction rate is obtained when variable parameters are applied in the Giesekus model at a high Weissenberg number.The Reynolds shear stress is reduced when the Weissenberg number increases.In this case,the turbulence generation and transportation are further weakened and increasingly approach to the values in the experiments. 展开更多
关键词 VISCOELASTIC FLUID Giesekus model direct NUMERICAL simulation(DNS) VARIABLE parameters
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变张力轴向运动Rayleigh梁组合参激共振的稳态响应 预览
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作者 王波 钱伟 蒋敏 《机械设计与制造》 北大核心 2019年第6期33-36,41共5页
研究非线性轴向变速黏弹性Rayleigh梁的参激振动问题。梁的本构关系使用Kelvin黏弹性模型描述,并且取全导数。基于广义哈密顿原理,导出轴向运动Rayleigh梁的非线性控制方程。考虑轴向速度在平均速度的基础上有简谐变化。运用直接多尺度... 研究非线性轴向变速黏弹性Rayleigh梁的参激振动问题。梁的本构关系使用Kelvin黏弹性模型描述,并且取全导数。基于广义哈密顿原理,导出轴向运动Rayleigh梁的非线性控制方程。考虑轴向速度在平均速度的基础上有简谐变化。运用直接多尺度法近似求解控制方程,并考虑轴向速度变化频率接近任意两阶固有频率之和时而发生的组合参激共振。依据可解性条件,得到振幅频率方程。通过对数值例子的分析,得到梁的刚度、扭转刚度以及平均速度对稳态响应的影响。 展开更多
关键词 轴向运动Rayleigh梁 黏弹性 多尺度法 组合参数共振 稳态响应
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BLOW-UP OF SOLUTION FOR A VISCOELASTIC WAVE EQUATION WITH DELAY 预览
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作者 吴舜堂 《数学物理学报:B辑英文版》 SCIE CSCD 2019年第1期329-338,共10页
In this paper, we consider the following viscoelastic wave equation with delay|ut|ρutt-△u-△utt+∫0t g(t-8)△u(8)d8 + μ1 ut(x,t) + μ2 ut(x,t-τ) = b|u|p-2 u in a bounded domain. Under appropriate conditions on μ... In this paper, we consider the following viscoelastic wave equation with delay|ut|ρutt-△u-△utt+∫0t g(t-8)△u(8)d8 + μ1 ut(x,t) + μ2 ut(x,t-τ) = b|u|p-2 u in a bounded domain. Under appropriate conditions on μ1, μ2, the kernel function g, the nonlinear source and the initial data, there are solutions that blow up in finite time. 展开更多
关键词 BLOW up nonlinear SOURCE WAVE EQUATION DELAY VISCOELASTIC
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Experimental study on the effects of shear stress on viscoelastic properties of the intestines
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作者 LI Jie BI XiaoNan +2 位作者 ZHANG Ke ZHANG Cheng LIU Hao 《中国科学:技术科学英文版》 SCIE EI CAS CSCD 2019年第6期1028-1034,共7页
Shear deformation induced by shear stress is one of the major forms of interaction between the locomotion mechanism and the intestines. Relatively few experimental studies using locomotion mechanisms have been perform... Shear deformation induced by shear stress is one of the major forms of interaction between the locomotion mechanism and the intestines. Relatively few experimental studies using locomotion mechanisms have been performed to investigate the viscoelastic property of intestines. There is a lack of reliable data regarding the relative movement between various locomotion mechanisms and the small intestine, and how that movement affects the measurement of shear displacement. In this work, a novel platform was constructed with two elaborately designed clamps that could securely fix both sides of an intestine sample using negative gas adsorption. The platform was also integrated with noncontact measuring equipment to record the thickness of the intestine sample. Subsequently, preservation measure was applied to porcine intestine, and multiple intestine samples were prepared and tested under strains of 20%, 50%, 80% and 100%. A five-element viscoelastic model that was fitted to multiple sets of data could accurately predict the biomechanical property of the intestines. Finally, a new criterion, the loss factor, was calculated with the parameters of the five-element model to represent the dynamic behavior of soft tissue, and it was used to verify the reliability and effectiveness of the experimental setup and results. 展开更多
关键词 SHEAR stress nonlinear VISCOELASTIC property INTESTINE LOSS factor NEGATIVE gas adsorption
Asymptotic Stability of Memory-Type Euler-Bernoulli Plate with Variable Coefficients and Time Delay
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作者 WANG Peipei HAO Jianghao 《系统科学与复杂性学报:英文版》 CSCD 2019年第5期1375-1392,共18页
This paper considers a viscoelastic Euler-Bernoulli plate system with variable coefficients and time-varying delay. By the multiplier method, Riemannian geometry method, and under suitable assumptions on viscoelastic ... This paper considers a viscoelastic Euler-Bernoulli plate system with variable coefficients and time-varying delay. By the multiplier method, Riemannian geometry method, and under suitable assumptions on viscoelastic term and time delay, the authors obtain the general stability of the solution for the system which depends on the behavior of the relaxation function. 展开更多
关键词 Euler-Bernoulli PLATE general decay rate time-varying DELAY variable coefficients viscoelastic term
A unified poroviscoelastic model with mesoscopic and microscopic heterogeneities
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作者 Boya Zhang Dinghui Yang +1 位作者 Yuanfeng Cheng Yunyin Zhang 《科学通报:英文版》 SCIE EI CSCD 2019年第17期1246-1254,共9页
The wave-induced fluid flow(WIFF) is considered to be the main cause of dispersion and attenuation of seismic waves in fluid-saturated porous media. Among numerous theories, the mesoscopic and microscopic heterogeneit... The wave-induced fluid flow(WIFF) is considered to be the main cause of dispersion and attenuation of seismic waves in fluid-saturated porous media. Among numerous theories, the mesoscopic and microscopic heterogeneities are considered to be the primary mechanisms causing the WIFF. Furthermore,in most rocks, the mesoscopic and microscopic heterogeneities exist simultaneously and can cause obvious transitions of the fast P-wave velocity, which means it is necessary to consider the influence of the two mechanisms on the dispersion and attenuation simultaneously. Numerous results have shown that the dispersions and attenuations caused by these two mechanisms can be approximated in terms of the Zener model. To combine the two mechanisms into a unified model, we introduce a new generalized Zener model into the Biot poroelasticity theory to obtain a new poroviscoelastic model. Comparisons between the numerical results and two groups of experimental data further confirm the validity of our new model. 展开更多
关键词 MESOSCOPIC HETEROGENEITY MICROSCOPIC HETEROGENEITY VISCOELASTIC MODEL Poroviscoelastic MODEL
Study on Postseismic Impact of Wenchuan Earthquake on the Sichuan-Yunnan Region Based on Three-Dimensional Viscoelastic Finite Element Method 预览
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作者 JIANG Fengyun ZHU Liangyu LI Yujiang 《中国地震研究:英文版》 CSCD 2019年第4期632-647,共16页
Based on the lateral segmentation and vertical stratification characteristics of the crustal medium in Sichuan-Yunnan region,and the asymmetry of the static dislocations on the coseismic fault plane of the Wenchuan M_... Based on the lateral segmentation and vertical stratification characteristics of the crustal medium in Sichuan-Yunnan region,and the asymmetry of the static dislocations on the coseismic fault plane of the Wenchuan M_S8.0 earthquake,we built a three-dimensional viscoelastic finite element model of the crust in the Sichuan-Yunnan region.The postseismic impact of the Wenchuan M_S8.0 earthquake on the Sichuan-Yunnan region was studied.The results show that:①The far-field horizontal deformation caused by the viscoelastic relaxation of the medium in the 10 years after the earthquake is about 0-20 mm within the Sichuan-Yunnan diamond-shaped block,which has a greater influence on north side and smaller on south side.②In the 10 years after the earthquake,the far-field vertical deformation caused by the viscoelastic relaxation effect of the medium is small,and it shows an increase of about 0-4 mm in most areas of the Sichuan-Yunnan diamond-shaped block.③The Xianshuihe fault and the eastern segment of the East Kunlun fault,which are close to the seismogenic fault,show a high gradient on deformation fields after the earthquake.④In order to compare with the strong earthquake activity in the SichuanYunnan region after the Wenchuan earthquake,the horizontal stress state and the Coulomb failure stress change of the active block boundary are also calculated.From the spatial distribution of the coseismic and postseismic displacement field,the fault activity characteristics reflected by the stress state and the stress loading of the fault layer reflected by the Coulomb failure stress change,there is a certain correlation with the spatial distribution of strong earthquake activity in this region. 展开更多
关键词 WENCHUAN MS8.0 earthquake Finite element VISCOELASTIC RELAXATION Sichuan-Yunnan region
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Extension Omega and Omega-Liutex methods applied to identify vortex structures in viscoelastic turbulent flow 预览
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作者 Lu Wang Zhi-ying Zheng +1 位作者 Wei-hua Cai Wan-you Li 《水动力学研究与进展:英文版》 SCIE EI CSCD 2019年第5期911-921,共11页
The vortex structure plays a significant role in the investigation of the turbulent drag reduction effect of the viscoelastic turbulent flow.This paper aims to find out an optimal vortex identification method for the ... The vortex structure plays a significant role in the investigation of the turbulent drag reduction effect of the viscoelastic turbulent flow.This paper aims to find out an optimal vortex identification method for the viscoelastic turbulent flows,and then studies the turbulent drag reduction mechanism by analyzing the characteristics of the identified vortex structures in the turbulent flows of the viscoelastic fluids.The Q,λ2,Liutex,Omega(Ω)and Omega-Liutex(ΩR)methods are adopted for the identification of vortex structures in the forced homogeneous isotropic turbulence(FHIT)with/without the polymer additive,respectively.The comparison among these five methods shows that the threshold values for the Q,λ2 and Liutex methods should be specially adjusted so as to suitably describe the strong and weak vortex structures in the FHIT of both the Newtonian and viscoelastic fluids,while a fixed threshold value of 0.52 for theΩandΩR methods is effective for both the Newtonian and viscoelastic fluids.The comparison between the identified vortex structures in the FHIT with and without the polymer additive indicates that theΩandΩR methods are more appropriate for the vortex identification because their dimensionless values with a fixed range from 0 to 1 can avoid the effect of the different ranges of the Q,λ2 and∣R∣(for the Liutex method)for the Newtonian and viscoelastic fluids.This also illustrates that theΩandΩR methods can be extended to identify the vortex structures in the turbulent flow of the viscoelastic fluid.Finally,the characteristics of the vortex structures in the FHIT of the viscoelastic fluid are analyzed by utilizing theΩandΩR methods.The results show that both the strong and weak vortex structures are inhibited by increasing the concentration of the polymer solution and by decreasing the Weissenberg number,especially for the weak vortex structures. 展开更多
关键词 Vortex identification OMEGA method(Ω) Omega-Liutex(ΩR)method forced homogeneous ISOTROPIC turbulence VISCOELASTIC fluid
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粘弹性材料动态体积模量测试方法研究进展
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作者 张栋洋 李登峰 王兵 《材料开发与应用》 CAS 2019年第1期106-112,共7页
分析了国内外相关文献,对目前粘弹性材料动态体积模量的测试方法进行了总结,并对未来测试技术的发展进行了简单展望。
关键词 粘弹性 体积模量 声学性能 测试方法
Seismic performance evaluation of typical dampers designed by Chinese building code 预览
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作者 Guo Wei Wu Jun +2 位作者 Hu Yao Li Yunsong Yang T.Y. 《地震工程与工程振动:英文版》 SCIE EI CSCD 2019年第2期433-446,共14页
Adding dampers is a commonly adopted seismic risk mitigation strategy for modern buildings, and the corresponding design procedure of dampers has been well established by the Chinese Building Code. Even though all typ... Adding dampers is a commonly adopted seismic risk mitigation strategy for modern buildings, and the corresponding design procedure of dampers has been well established by the Chinese Building Code. Even though all types of dampers are designed by the same procedure, actual seismic performance of the building may differ from one to the others. In this study, a nine-story benchmark steel building is established, and three different and typical types of dampers are designed according to the Chinese Building Code to realize structural vibration control under strong earthquake excitation. The seismic response of the prototype building equipped with a viscoelastic damper, viscous damper and buckling-restrained brace(BRB) subjected to 10 earthquake records are calculated, and Incremental Dynamic Analysis(IDA) is performed to describe progressive damage of the structure under increasing earthquake intensity. In the perspective of fragility, it shows that the viscoelastic damper has the highest collapse margin ratio(CMR), and the viscous damper provides the best drift control. Both the BRB and viscoelastic dampers can effectively reduce the floor acceleration responses in the mid-rise building. 展开更多
关键词 CHINESE building design code viscoelastic DAMPER VISCOUS DAMPER buckling-restrained BRACE seismic response FRAGILITY analysis
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Stationary response of stochastic viscoelastic system with the right unilateral nonzero offset barrier impacts
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作者 王德莉 徐伟 谷旭东 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第1期195-204,共10页
The stationary response of viscoelastic dynamical system with the right unilateral nonzero offset barrier impacts subjected to stochastic excitations is investigated. First, the viscoelastic force is approximately tre... The stationary response of viscoelastic dynamical system with the right unilateral nonzero offset barrier impacts subjected to stochastic excitations is investigated. First, the viscoelastic force is approximately treated as equivalent terms associated with effects. Then, the free vibro-impact(VI) system is absorbed to describe the periodic motion without impacts and quasi-periodic motion with impacts based upon the level of system energy. The stochastic averaging of energy envelope(SAEE) is adopted to seek the stationary probability density functions(PDFs). The detailed theoretical results for Van der Pol viscoelastic VI system with the right unilateral nonzero offset barrier are solved to demonstrate the important effects of the viscoelastic damping and nonzero rigid barrier impacts condition. Monte Carlo(MC) simulation is also performed to verify the reliability of the suggested approach. The stochastic P-bifurcation caused by certain system parameters is further explored. The variation of elastic modulus from negative to zero and then to positive witnesses the evolution process of stochastic P-bifurcation. From the vicinity of the common value to a wider range, the relaxation time induces the stochastic P-bifurcation in the two interval schemes. 展开更多
关键词 viscoelastic system RIGHT UNILATERAL nonzero offset BARRIER IMPACTS STOCHASTIC AVERAGING of energy envelope(SAEE) STOCHASTIC P-bifurcation
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