新型耗能(阻尼)减震器的开发与研究   总被引：18，自引：7，他引：11  

周云  刘季 《地震工程与工程振动》1998,18(1):71-79

本文阐述了耗能减震的概念和原理,提出了耗能减震器设计的新思想,研制开发了多种新型实用耗能（阻尼）减震器,并对其中的圆环耗能器、双环耗能器、架颈圆环耗能器、弹塑性－摩擦复合耗能器等进行了循环荷载试验,考察了耗能器代作性能和耗能性能,对已装与未装耗能减震器的钢筋混凝土框架模型进行了伪动力对比实验,进一步考察了耗能减震器的减震效果。在试验研究的基础上,地耗能（阻尼）减震结构体系的分析方法进行了研究,并编  相似文献   

Development in modeling cyclic loading of sands based on kinematic hardening     

Mohammad Maleki  Bernard Cambou  Philppe Dubujet 《国际地质力学数值与分析法杂志》2009,33(14):1641-1658

In this paper, there is presented an elastoplastic constitutive model to predict sandy soils behavior under monotonic and cyclic loadings. This model is based on an existing model (Cambou‐Jafari‐Sidoroff) that takes into account deviatoric and isotropic mechanisms of plasticity. The flow rule used in the deviatoric mechanism is non‐associated and a mixed hardening law controls the evolution of the yield surface. In this research the critical state surface and history surface, which separates the virgin and cyclic states in stress space, are defined. Kinematic hardening modulus and stress–dilatancy law for monotonic and cyclic loadings are effectively modified. With taking hardening modulus as a function of deviatoric and volumetric plastic strain and with defining the history surface and stress reversal, the model has the ability to predict the sandy soils' behavior. All of the model parameters have clear physical meanings and can be determined from usual laboratory tests. In order to validate the model, the results of homogeneous tests on Hostun and Toyoura sands are used. The results of validation show a good capability of the proposed model. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

A new approximation for pore pressure accumulation in marine sediment due to water waves     

D.‐S. Jeng  B. R. Seymour  J. Li 《国际地质力学数值与分析法杂志》2007,31(1):53-69

The residual mechanism of wave‐induced pore water pressure accumulation in marine sediments is re‐examined. An analytical approximation is derived using a linear relation for pore pressure generation in cyclic loading, and mistakes in previous solutions (Int. J. Numer. Anal. Methods Geomech. 2001; 25 :885–907; J. Offshore Mech. Arctic Eng. (ASME) 1989; 111 (1):1–11) are corrected. A numerical scheme is then employed to solve the case with a non‐linear relation for pore pressure generation. Both analytical and numerical solutions are verified with experimental data (Laboratory and field investigation of wave– sediment interaction. Joseph H. Defrees Hydraulics Laboratory, School of Civil and Environmental Engineering, Cornell University, Ithaca, NY, 1983), and provide a better prediction of pore pressure accumulation than the previous solution (J. Offshore Mech. Arctic Eng. (ASME) 1989; 111 (1):1–11). The parametric study concludes that the pore pressure accumulation and use of full non‐linear relation of pore pressure become more important under the following conditions: (1) large wave amplitude, (2) longer wave period, (3) shallow water, (4) shallow soil and (5) softer soils with a low consolidation coefficient. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

复杂应力条件下长江口原状饱和软黏土门槛循环应力比试验研究     

刘功勋  栾茂田  郭莹  王忠涛  贺林  张俊峰 《岩土力学》2010,31(4):1123-1129

针对取自于长江口的海洋原状饱和软黏土,利用土工静力-动力液压三轴-扭转多功能剪切仪,在控制不同初始固结参数的三向非均等固结状态和不排水条件下,分别进行了轴向和扭转双向耦合循环剪切以及循环扭剪等多种复杂循环剪切试验。分别研究了初始大主应力方向角、初始偏应力比、初始中主应力系数以及循环剪切应力模式等因素对门槛循环应力比的影响。试验结果表明,在三向非均等固结条件下,初始大主应力方向角、初始偏应力比对门槛循环应力比影响显著,门槛循环应力比随着初始大主应力方向角与初始偏应力比的增大而明显减小;而初始中主应力系数对门槛循环应力比基本没有影响。循环剪切应力模式对门槛循环应力比具有显著影响,在相同的初始固结应力条件下,循环耦合剪切试验确定的门槛循环应力比明显小于循环扭剪试验所确定的门槛循环应力比。  相似文献   

分段多项式拟合在动三轴试验数据处理中的应用     

周松望  周杨锐  吴海京  戴少军  沈志明  董明明 《海洋学报》2014,36(5):186-189

动三轴采集的试验数据点(剪应变与动剪模量和阻尼比之间)具有离散性和有限性,为方便应用需要对数据点进行拟合,但现有经验公式不一定很好吻合试验数据。为得到不同剪应变与对应的动剪模量和阻尼比之间的关系,本文利用最小二乘原理,对渤海某海洋平台地基土进行动三轴试验获得的动剪模量、阻尼比与剪切应变的数据进行了分段多项式的拟合。数据处理过程是先对剪应变值进行了压缩处理,然后再分段低次多项式拟合,得到多项式拟合参数。通过此项改进解决了正规方程解中的病态问题,且拟合效果良好。  相似文献   

低频循环荷载下盐岩轴向蠕变的Burgers模型分析     

王军保  刘新荣  黄明 《岩土力学》2014,35(4):933-942

为了研究盐岩在低频循环荷载作用下的蠕变特性,采用恒轴压、循环围压的应力加载方式对盐岩开展了低频循环荷载蠕变试验。试验结果显示,当蠕变时间较短时,盐岩轴向蠕变曲线近似为平滑曲线,波动性不大;当时间增加到一定程度以后,盐岩变形随围压变化而发生明显的波动。总体来看,循环荷载下盐岩轴向蠕变曲线与Burgers模型蠕变曲线较为相似。将Burgers模型分解为Maxwell模型和Kelvin模型,忽略材料的疲劳效应,分别推导了恒轴压、循环围压应力加载方式下Maxwell模型和Kelvin模型的轴向蠕变方程,分析了荷载循环周期对模型蠕变性的影响规律;将循环荷载下Maxwell模型和Kelvin模型的轴向蠕变方程进行叠加,得到了循环荷载下Burgers模型的轴向蠕变方程,并利用盐岩蠕变试验结果对其合理性进行了验证。结果表明:拟合曲线和试验曲线吻合良好,该模型能够较好地反映盐岩在循环荷载作用下的蠕变特性和荷载变化对盐岩蠕变性的重要影响,特别是能够反映出不同荷载循环周期下盐岩变形随荷载变化而发生的明显的波动现象。  相似文献   

A simplified analysis of interface failure under compressive normal stress and monotonic or cyclic shear loading     

Zenon Mrz  Marcin Bia&#x;as 《国际地质力学数值与分析法杂志》2005,29(4):337-368

Interface damage and delamination is usually accompanied by frictional slip at contacting interfaces under compressive normal stress. The present work is concerned with an analysis of progressive interface failure using the cohesive crack model with the critical stress softening and frictional traction present at the contact. Both monotonic and cyclic loadings are considered for anti‐plane shear of an elastic plate bonded to a rigid substrate by means of cohesive interface. An analytical solution can be obtained by neglecting the effect of minor shear stress component. The analysis of progressive delamination process revealed three solution types, namely: short, medium and long plate solutions. The long plate solution was obtained under an assumption of quasistatic progressive growth of the delamination zone. In view of snap back response, the quasistatic deformation process cannot be executed by either traction or displacement control. The states of frictional slip accompanied by shake down or incremental failure are distinguished in the case of cyclic loading, related to load amplitude and structural dimensions. The analysis provides a reference solution for numerical treatment of more complex cases. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

基于A- CGAN的深反射地震数据随机噪声压制方法研究     

韩建光  王卿  许媛  刘志伟 《地质论评》2023,69(4):2023040015-2023040015

基于深度学习的地震数据噪声压制方法是当前地震数据去噪处理的重要方向。深度学习方法突破了传统滤波处理的局限,在对常规地震数据的噪声压制中表现出效率高、信噪分离效果好的特点。但针对深部弱有效反射数据,当前的深度学习方法特征提取能力有限,难以取得较好的去噪效果。笔者等结合深反射地震数据特点,针对当前深度学习噪声压制方法在特征提取及对数据集依赖上的局限,提出了基于注意力循环生成对抗网络(Attention Cycle- Consistent Generative Adversarial Networks,A- CGAN)的深反射地震数据随机噪声压制方法。借助循环一致生成对抗网络(Cycle- Consistent Generative Adversarial Networks,Cycle- GAN)的域映射思想,降低对数据集的要求。为了构建适用于深反射地震数据的去噪网络,从3个方面对Cycle- GAN进行改进：在Cycle- GAN的生成器（去噪器）中加入残差结构和注意力机制,用于加深网络深度和提高其特征提取能力;在Cycle- GAN的鉴别器中使用块判决,提高鉴别精度和准确度;在损失函数部分加入感知一致性损失函数,提升网络模型恢复纹理细节信息的能力。通过合成地震数据和实际深反射地震数据测试,验证了优化算法的有效性,体现了良好的应用价值。  相似文献   

基于OpenSees的砂土本构模型对比研究          下载免费PDF全文

周林禄  苏雷  邱志坚  凌贤长  张安琪 《地震工程学报》2022,44(1):128-135

饱和砂土液化是由地震引起的一种最常见的工程地质现象,也是造成重大地震灾害的主要原因之一。由于成因的复杂性和所造成灾害的严重性,饱和砂土液化一直是土动力学和岩土地震工程研究领域的重要课题。针对饱和砂土液化问题,基于开源地震工程数值计算平台OpenSees,对材料库中的4种砂土本构模型进行数值计算。采用二维u-p单元模拟土颗粒位移和孔隙水压力,分析和对比4种模型在循环动力荷载作用下的加速度、超孔隙水压力、位移、剪应力-剪应变和平均有效应力路径方面的响应结果。研究结果表明:(1)砂土对输入加速度表现出一定的放大效应,对于不同的模型,该放大效应存在一些差异;(2) Stress Density模型在循环动力荷载作用下易产生永久变形;(3)在循环动力荷载作用下,PDMY模型和CycLiqCPSP模型的强度逐渐降低,直到完全消失;(4) Stress Density模型和Manzari Dafalias模型在循环动力荷载下表现出明显的剪胀效应。研究成果对砂土液化的数值模拟问题具有重要的理论价值,可为饱和砂土的液化模拟和砂土本构模型的选取提供参考。  相似文献   

剪切屈服型可更换耗能梁的抗震性能研究          下载免费PDF全文

熊礼全  陈晓健  贾真  李林燕  梁永清  门进杰 《世界地震工程》2022,38(4):065-71

针对传统结构震后修复能力不足,带可更换构件的混合框架结构体系在地震作用下,可更换耗能构件集中损伤和耗散地震能量,保护其他构件不损伤或轻微损伤,更换损伤的耗能构件,即可实现结构预定功能震后可恢复。通过3个可更换耗能梁试件,研究其抗震性能。在此基础上,通过SAP2000有限元建模,对带可更换构件的混合框架结构进行非线性分析,研究整体结构体系的屈服机制、承载力和可更换耗能构件的可更换性能。结果表明:试件均发生剪切屈服型破坏,破坏特征包括腹板－加劲肋焊缝撕裂、腹板屈曲和腹板撕裂。各试件的滞回曲线非常饱满,具有优异的承载能力、变形能力和耗能能力;在地震作用下,带可更换构件的混合框架结构体系中各构件能够实现良好的有序屈服机制,可更换耗能构件具有较好的可更换性。  相似文献