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动态应力作用与地震机制的初步研究 被引量:19
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作者 陆明勇 郑文衡 胡志奇 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2006年第1期170-179,共10页
运用三维非线性动态有限元计算仿真方法研究了动态应力的作用及其与地震机制的关系.结果表明地震产生的冲击力在加载与卸载过程中形成的应力波,在遇断层时多次反射并发生半波损失,反射的应力波叠加或干涉而形成的动态应力使围压减小和波... 运用三维非线性动态有限元计算仿真方法研究了动态应力的作用及其与地震机制的关系.结果表明地震产生的冲击力在加载与卸载过程中形成的应力波,在遇断层时多次反射并发生半波损失,反射的应力波叠加或干涉而形成的动态应力使围压减小和波动.地震动态应力使围压产生低值波动,一方面使围压减小、摩擦力减小;另一方面,使裂纹串通、介质松动、接触面变平,降低摩擦系数、减小剪切强度.由此均导致抗剪强度降低,从而触发地震.动态应力作用时间短,触发地震大小与动态应力大小成正比、与距离成反比,触发地震位置、过程与孕震体断层产状有关. 展开更多
关键词 三维非线性动态有限元方法 动态应力作用 低值波动 地震机制 断层产状
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玛尼Ms7.9级地震三维动态模拟及余震解释 被引量:2
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作者 张晓亮 陆明勇 +2 位作者 江在森 王双绪 祝意青 《地球物理学进展》 CSCD 北大核心 2008年第5期1367-1376,共10页
以1997年玛尼地震为例,利用三维非线性动态有限元方法,再现了玛尼地震的破裂过程.研究结果表明:(1)玛尼地震产生的动态应力波随时间变化呈明显波动性且随距离衰减,沿断裂带衰减相对慢一些.其波动性是震源区不同相位应力波及一些反射波... 以1997年玛尼地震为例,利用三维非线性动态有限元方法,再现了玛尼地震的破裂过程.研究结果表明:(1)玛尼地震产生的动态应力波随时间变化呈明显波动性且随距离衰减,沿断裂带衰减相对慢一些.其波动性是震源区不同相位应力波及一些反射波相互叠加造成的.震源区动应力强烈的波动性使破裂表现"愈合脉冲"特征.(2)玛尼地震与其后几年发生的中强余震关系密切.2001年3月5日在大震西南方向发生Ms6.4级地震、阿尔金断裂西段1999年与2000年的两次中强地震可能均主要是玛尼地震的产物.(3)玛尼地震对昆仑大震孕震区的动应力影响,卸载前产生的动应力变化大约为0.05 MPa,其远大于静应力的地震触发阈值,卸载后动应力剧烈波动,上下波动达0.2 MPa左右,其大约相当于0.02 MPa的静应力,这是静应力触发地震阈值的2倍,揭示玛尼地震很大程度上触发了昆仑大震的提前发生. 展开更多
关键词 三维非线性动态有限元方法 玛尼地震 动应力 应力波动 地震 动应变
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基于唐山7.8级地震探讨动态应力作用 被引量:1
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作者 陆明勇 郑文衡 +5 位作者 陈连旺 牛安福 詹自敏 李民 寇建新 房综绯 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2010年第9期2110-2118,共9页
运用三维非线性动态有限元方法(Non-linear Dynamic FEM)仿真模拟研究了菱形模型的动态应力作用,分析了1976年唐山7.8级地震.结果表明:(1)唐山地震前增强的中强地震产生的冲击力形成的应力波反射后发生半波损失,成为动态的拉伸应力,通... 运用三维非线性动态有限元方法(Non-linear Dynamic FEM)仿真模拟研究了菱形模型的动态应力作用,分析了1976年唐山7.8级地震.结果表明:(1)唐山地震前增强的中强地震产生的冲击力形成的应力波反射后发生半波损失,成为动态的拉伸应力,通过减小内摩擦而引起岩石产生裂纹、局部破裂并发生串通,一方面触发地震,另一方面为孕育唐山地震积累能量,表现为正反馈过程.(2)唐山地震产生的冲击力加卸载存在时间差,造成加卸载冲击波相位不同,结果产生的动应力和围压叠加致使围压波动和下降,导致抗剪切强度降低,使初始破裂分别向北东、西南方向传播.(3)冲击力的卸载,相对于产生拉伸性的应力波,反射后发生半波损失,成为动态的压缩应力,致使围压增大并导致破裂停止;而动态应力在传播过程中衰减.因此,余震的发生是一个负反馈过程. 展开更多
关键词 唐山地震 三维非线性动态有限元方法 动态应力作用 低值波动
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超低空空投过程的仿真 被引量:22
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作者 杨雪松 王乘 李振环 《华中科技大学学报(自然科学版)》 EI CAS CSCD 北大核心 2003年第4期108-110,共3页
运用动态有限元方法 ,对救灾物资的超低空空投过程进行了数值仿真 .初步建立了超低空空投过程的计算模型 ,计算模拟了实际的典型空投条件及空投过程 .根据仿真结果对飞机空投安全性、着地冲击载荷和减速效果进行了分析 。
关键词 超低空空投系统 减速 空投过程 数值仿真 动态有限元方法 飞机安全性 救灾物资 着地冲击载荷
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地壳对海洋潮汐的响应(英文) 被引量:4
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作者 郑文衡 王乘 +1 位作者 何振 牛安福 《大地测量与地球动力学》 CSCD 2002年第2期41-46,共6页
应用三维动态有限元方法研究了中国北部地区的地壳对邻近的渤海与黄海海平面变化的响应。虽然此应力场过于微弱不足以引发地震 ,但发现应力集中的位置及应力场变化较大的位置恰好与某些现代地震的震中一致。
关键词 地壳 三维动态有限元方法 中国北部 潮汐 地震 非线性 应力场
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物理上真实,数学上简洁——考虑复杂性问题的基本思路
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作者 郑文衡 陈湘鹏 《国际地震动态》 2001年第4期4-6,共3页
就地壳及其动力学过程的复杂性 ,结合地震预报与机理的研究现状和方法 ,提出了个人的看法 。
关键词 复杂性 非线性动态有限元方法 地震预报机理 地壳动力学
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Computational simulation of convective flow in the Earth crust under consideration of dynamic crust-mantle interactions 被引量:1
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作者 赵崇斌 彭省临 +2 位作者 刘亮明 B.E.HOBBS A.ORD 《Journal of Central South University》 SCIE EI CAS 2011年第6期2080-2084,共5页
The finite element method was used to solve fluid dynamic interaction problems between the crust and mantle of the Earth. To consider different mechanical behaviours, the lithosphere consisting of the crust and upper ... The finite element method was used to solve fluid dynamic interaction problems between the crust and mantle of the Earth. To consider different mechanical behaviours, the lithosphere consisting of the crust and upper mantle was simulated as fluid-saturated porous rocks, while the upper aesthenospheric part of the mantle was simulated as viscous fluids. Since the whole lithosphere was computationally simulated, the dynamic interaction between the crust and the upper mantle was appropriately considered. In particular, the mixing of mantle fluids and crustal fluids was simulated in the corresponding computational model. The related computational simulation results from an example problem demonstrate that the mantle fluids can flow into the crust and mix with the crustal fluids due to the resulting convective flows in the crust-mantle system. Likewise, the crustal fluids can also flow into the upper mantle and mix with the mantle fluids. This kind of fluids mixing and exchange is very important to the better understanding of the governing processes that control the ore body formation and mineralization in the upper crust of the Earth. 展开更多
关键词 computational simulation crustal fluids mantle fluids fluid dynamic interaction
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Simulation of 3D Needle-Tissue Interaction with Application to Image Guided Prostate Brachytherapy
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作者 姜杉 HATA Nobuhiko +1 位作者 肖渤瀚 安蔚瑾 《Transactions of Tianjin University》 EI CAS 2010年第1期28-32,共5页
To improve global control of disease and reduce global toxicity, a complex seed distribution pattern should be achieved with great accuracy during brachytherapy.However, the interaction between the needle and prostate... To improve global control of disease and reduce global toxicity, a complex seed distribution pattern should be achieved with great accuracy during brachytherapy.However, the interaction between the needle and prostate will cause large deformation of soft tissue.As a result, seeds will be misplaced, sharp demarcation between irradiated volume and healthy structures is unavailable and this will cause side effects such as impotence and urinary incontinence.In this paper, a 3D nonlinear dynamic finite element s... 展开更多
关键词 BRACHYTHERAPY soft tissue finite element method dynamic simulation
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Parametric analysis of steel plated shear structures
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作者 M.Ghassemieh N.Heidari 《Journal of Central South University》 SCIE EI CAS 2014年第5期2083-2090,共8页
Due to outstanding ductility and high strength,the steel plate shear wall(SPSW)is recognized as a good lateral system for building structures; particularly as it interacts with earthquake resistant design.This study a... Due to outstanding ductility and high strength,the steel plate shear wall(SPSW)is recognized as a good lateral system for building structures; particularly as it interacts with earthquake resistant design.This study aims to reveal the dynamic and cyclic behavior of steel plated shear wall.Finite element method of analysis was implemented in order to simulate the behavior of such a wall structure.To determine the dynamic behavior of un-stiffened plate shear wall,two different analytical models were implemented.The post buckling strength of steel plate subjected to lateral loading was also employed.The story shear-drift diagrams of steel shear wall system were presented.The strength and ductility of the system obtained from the analysis were compared with those of steel shear wall tests reported before.The pertinent parameters of the steel shear wall system such as plate thickness,column and beam stiffness and the plate aspect ratio were recognized and their effects were recorded.The effect of stiffeners on the behavior of the SPSW was also investigated. 展开更多
关键词 steel shear wall pushover analysis energy dissipation DUCTILITY post buckling behavior Strut element
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Dynamic modeling and H_∞ independent modal space vibration control of laminate plates 被引量:1
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作者 RONG Bao RUI XiaoTing +1 位作者 WANG GuoPing YANG FuFeng 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2011年第9期1638-1650,共13页
In this paper, combining the transfer matrix method and the finite element method, the modified finite element transfer matrix method is presented for high efficient dynamic modeling of laminated plates. Then, by cons... In this paper, combining the transfer matrix method and the finite element method, the modified finite element transfer matrix method is presented for high efficient dynamic modeling of laminated plates. Then, by constructing the modal filter and the disturbance force observer, and using the feedback and feedforward approaches, the H ∞ independent modal space control strategy is designed for active vibration control of laminate plates subjected to arbitrary, immeasurable disturbance forces. Compared with ordinary dynamic modeling and control methods of laminated plate structures, the proposed method has the low memory requirement, high computational efficiency and robust control performance. Formulations as well as some numerical examples are given to validate the method and the control performance. 展开更多
关键词 transfer matrix method finite element laminated plate active vibration control H~ control
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