静电陀螺仪实心球转子变形分析

介绍了静电陀螺仪实心球转子的两种典型结构，并利用有限元仿真工具根据工作环境对这两种结构分别进行了离心变形、温度变形、压力变形以及这三种载荷的耦合变形的仿真分析。得出了实心球转子的变形规律及变形量，为转子的设计和静电陀螺的建模提供了重要的参考依据。     

消减舰船变形的影响和为全舰提供高精度姿态基准

引用国内外一些文献列举的现代舰船船体变形的数据，论证了消减船体变形的影响和为全舰提供精确的姿态基准的重要意义。对舰载航向姿态基准的功能、性能与特点进行了综述。介绍了基于激光陀螺和光纤Bragg光栅传感器测量船体变形的新方法。最后，探讨了分布式姿态基准系统的技术方案。     

非经典大变形弹塑性本构方程及其算法研究

本文介绍了作者提出的非经典大变形弹塑性木构方程的增量形式，发展了相应的有限元分析方法。由于不采用屈服面的概念及相应的流动规律与加载准则，与传统的算法相比，本文提出的算法不仅简化了计算过程，而且改善了收敛速度和计算精度。作为验证和应用的例子，分析了圆柱试件的大变形拉伸颈缩过程和短圆柱的镦粗过程。与实验结果的比较证明了所发展方法的有效性。     

心肌细胞大变形黏弹性模型及在实验中的应用

在衡量单个细胞力学行为的研究中,越来越多地采用结合实验的数值模拟方法. 在连续介质力学框架下,发展了一种新的心肌细胞本构模型,并与微管吮吸实验结合,探讨了心肌细胞的力学特性. 本构模型是对普遍使用的仅能用于小变形分析的标准线性固体模型的一种扩展,它将超弹性性能引入到黏弹性模型中,用以描述细胞的大变形黏弹性效应. 基于改进的本构模型,对心肌细胞微管吮吸实验过程进行了有限元模拟,并将计算结果与实验结果以及经典理论解进行了对比. 结果显示发展的本构模型适合细胞大变形问题的有限元数值模拟.      

梁板壳的几何大变形--从近似的非线性理论到有限变形理论

对梁板壳的线性理论、近似几何非线性理论与有限变形理论作了比较,介绍了有限转动理论,指出了应用有限变形理论求解梁板壳的大变形问题的高效率、高精度的巨大优越性。     

一种箱体类零件装配变形的测试与分析方法

箱体类零件装配后,可能发生变形,改变其冷加工时的质量控制。本文以６１０５柴油机机体曲轴箱为例,介绍一种测试和描述箱体类零件装配变形的计算机辅助方法     

一种箱体为零件装配变形的测试与分析方法

箱体类零件装配后,呆能发生变形,改变其冷加工时的质量控制。本文以６１０５柴油机机体曲轴箱为例,介绍一种测试和描述箱体类零件装配变形的计算机辅助方法。     

爆炸载荷下大变形的阴影云纹测量术

本文介绍了用阴影云纹法测量爆炸载荷下铝板变形的方法及结果,并进行了误差讨论和静态标定。     

采动区建筑物抗变形隔震装置的力学性能分析

介绍了采动区建筑物抗变形隔震装置的基本构成,并基于地震工程学和开采沉陷学的原理对抗变形隔震支座进行了理论分析,通过实验对采动区抗变形隔震支座在低周反复荷载作用下的滞回耗能特性进行了分析。结果显示,在低周循环荷载作用下采动区抗变形隔震支座的滞回耗能曲线饱满,表明其良好的自复位、耗能能力和变形能力大、稳定的滞回性能等特点,说明抗变形隔震支座的传力机制明确、构造比较合理。隔震支座充分利用了铅芯橡胶、粘滞阻尼器和蝶形弹簧三种不同的耗能材料和耗能机制,其适宜的水平隔震刚度和阻尼耗能性能、竖向能够抵抗不均匀沉降,充分体现了其良好的整体稳定性。该抗变形隔震支座有效的改善了采动区建筑抵抗煤矿采动损害和震害的能力,为采动区建筑物保护提供科学方法和依据。     

现代土力学的基本问题

现代土力学可望在今后３０年内建成基本框架，其主要内容将包括亲后代的本构模型及一个变形理论和两个破坏理论，本文介绍了作者对这此问题的今后研究重点及发展的一些看法。     

Microfabricated Force Sensors and Their Applications in the Study of Cell Mechanical Response

Living cells are sensitive to their mechanical environments and they transduce mechanical stimuli into biological responses. Developing suitable experimental techniques is essential to explore the question on how cells respond to mechanical stimuli. The current major techniques normally induce small cell deformations and measure their corresponding cell force response (small) in the range of 1 pN to 10nN. However, in many physiological conditions, cell deformations can be large (comparable to the cell sizes) inducing large force response. In order to explore cell mechanical behavior under large deformations, we introduce a class of microfabricated force sensors. The sensors, consisting of a probe and flexible beams, normally measure cell force response in the range of 1nN to 1μN. Both the one- and two-component force sensors have been developed, and have been used in cell experiments. These experiments showed the versatility of the force sensors. Representative experimental results on cell stretch force response, cell indentation force response, and in situ observation of the actin cytoskeleton during indentation, will be given. These results provide significant insight on cell mechanical response under large deformations.     

Differential quadrature method for bending of orthotropic plates with finite deformation and transverse shear effects

Based on the Reddy ‘s theory of plates with the effect of higher-order shear deformations, the governing equations for bending of orthotropic plates with finite deformations were established. The differential quadrature ( DQ ) method of nonlinear analysis to the problem was presented. New DQ approach, presented by Wang and Bert ( DQWB), is extended to handle the multiple boundary conditions of plates. The techniques were also further extended to simplify nonlinear computations. The numerical convergence and comparison of solutions were studied. The results show that the DQ method presented is very reliable and valid. Moreover, the influences of geometric and material parameters as well as the transverse shear deformations on nonlinear bending were investigated. Numerical results show the influence of the shear deformation on the static bending of orthotropic moderately thick plate is significant.     

粘弹塑性统一本构模型理论

文章在已有的统一本构模型的基础上,将粘弹性变形引入到统一本构模型之中,成功地改善了材料过渡段的变形模拟情况。通过Hastelloy-X的变形模拟及与其它统一本构模型的变形模拟比较,证明了粘弹塑性统一本构模型的合理性。     

Confined compression: A stable homogeneous deformation for constitutive characterization

An experimental configuration is described in which the complete state of stress and strain in the specimen are determined through direct experimental measurement, without a priori constitutive assumptions with regard to the material behavior. Moreover, the control of the deformations is such that the deformations are always stable. Design considerations in implementing such an experimental configuration and applications to the investigation of the multiaxial constitutive behavior in materials are also described. An-example of the implementation is demonstrated using Al 6061-T6 alloy.     

蒲石河混凝土面板堆石坝沉降特性分析

为了研究堆石坝竣工期的垂直和水平变形特性,采用ABAQUS 软件中的单元生死方法数值模拟了堆石坝的分层浇筑过程. 建立了堆石坝变形与上游水位、环境温度和时效之间的非线性关系模型. 采用多元非线性回归分析方法,根据现场观测数据确定了堆石坝变形模型中的参数. 研究表明,堆石坝沉降变形具有较好的规律性,沉降变形预测模型预测结果与现场观测值基本一致.     

考虑非线性变形的航天器柔性附件建模方法

针对航天器的柔性附件,将其简化为常见的大范围运动空间柔性梁结构。根据柔性体的非线性变形原理,考虑了弯曲和扭转的非线性因素的影响,在柔性梁的三个变形方向上均考虑了变形的二次耦合项。利用有限元方法进行离散并用Lagrange方程建立了非线性变形模式下的动力学方程,包含了较为完全的刚度矩阵和各种耦合项。对一大范围运动的空间梁进行了仿真计算,表明在运动速度较大并且基座具有大范围运动时,一次耦合模型与本文模型有一定差异,且初始变形对两种模型也会产生影响。     

DDA与FEM耦合法在分缝重力坝非线性分析中的应用

混凝土重力坝一般设有数条纵缝。纵缝使坝体的连续性遭到破坏，一般的有限单元法很难处理这样的不连续变形问题。本文首先阐述了DDA(Discontinuous Deformation Analysis)与FEM(Finite Element Method)耦合算法的原理，然后采用作者自行研制的DDA与FEM耦合法程序对一实际重力坝进行了详细的计算分析。重点讨论了纵缝的不同设置形式和缝宽大小对坝体变形和应力分布、坝底面接触应力分布以及坝基面应力分布的影响，为工程设计提供依据。     

敦煌莫高窟北区岩体变异变形及修复对策

敦煌莫高窟北区岩体长期以来在特殊的地形地貌、气象水文、岩土性质、地质构造条件下,受人工开挖、重力、风蚀、雨蚀和洪水冲刷等共同作用,岩体发生风化、卸荷等变异以及崩塌、坍塌和危岩、开裂与裂隙(构造裂隙、卸荷裂隙)等多种变形,严重影响岩体的稳定和洞窟的安全。针对上述变异、变形破坏情况,采用PS材料加粉煤灰浆液灌浆封闭裂隙和岩面喷浆加固相结合的修复方法,有效地防止了岩体变异的进一步扩展和表面风化的加剧,减少了岩体变形和表面风化程度,使石窟得以保护和修复。该方法对黄土及干旱地区石窟保护具有良好的借鉴作用。     

Finite elastoplastic deformation of an internally pressurized hollow sphere

This paper considers large elastoplastic deformations of an internally pressurized hollow sphere of dilatant soil. A complete analytical solution for the expansion of a hollow sphere is developed. The soil is modelled as an elastic-perfectly plastic material obeying the Mohr-Coulomb yield criterion. A non-associated plastic flow rule is used and therefore the dilation of the material is fully taken into account. Closed form solutions are obtained for the stresses and the elastic-plastic deformations of arbitrary magnitude when a hollow sphere of soil is subjected to constant external pressure and monotonically increasing internal pressure. A selection of numerical results is presented to indicate the effects of various key parameters     

Homogeneous deformation of a two-fluid plasma with allowance for electron inertia

A method of finding the homogeneous deformations of a two-fluid plasma with allowance for the electron inertia is proposed. By homogeneous deformation is meant an axisymmetric plasma flow with a linear dependence of the radial velocity on the radius. Three families of homogeneous deformations are found using this method. One of these families, consisting of deformations with an arbitrary law of variation of the total current, is of particular interest with reference to plasma column dynamics. The method proposed is based on the reduction of the equations of two-fluid plasma dynamics to single-fluid equations of the hydrodynamic type (the equations of electromagnetic hydrodynamics (EMHD)) with a non-diagonal internal stress tensor, three-parameter thermodynamics, and a nonlocal form of the generalized Ohm’s law. Possible applications of the exact solutions found to the analysis of the data obtained using certain experimental apparatus are discussed.