屈曲

The primary objective of this study is to analyze the buckling mode of inclined lipped purlins and predict distortional buckling strengths, as compared to the consequence calculated by ANSYS.

本文以此作为出发点，对卷边檩条的弹性屈曲进行了理论分析，并应用ANSYS有限元法计算总结了斜卷边檩条翼缘屈曲系数的合理取值方法。

This study validate that it also can be used for distortional buckling beam-column under the condition of distortional buckling load calculated by the above formula.

本文用直接强度法来计算压弯构件在发生畸变屈曲时的承载能力，把计算结果同有限元模拟结果进行对比，验证在压弯构件畸变屈曲时直接强度法的适用性。

Methods: The parameters of patellofemoral joints (normal group: 30; abnormal group: 20) were studied at the 0, 6, 12, 18, 24, 30 and 36 degrees of flection with MR in axial plane and MPW, LPA, FTA, PTA, FTD were measured, then, compared in the normal and abnormal ups.

对两组（正常组30个，病例组20个）膝关节分别在被动屈曲0，6，12，18，24，30，36下进行轴位动态MRI检查，测量髌骨最大径，外侧髌股角，股骨滑车沟角，髌骨倾斜角，股骨滑车沟深度，分别比较正常组及病例组在七个不同屈曲角度下各测量参数的差异性。

The nonlinear dynamic equations including the initial geometric imperfections of laminated composite cylindrical shells were derived from Hamilton's philosophy. Assuming the transverse displacements to be composed of axially symmetrical part and axially asymmetrical part, the governing equations expressed as displacement forms of dynamic buckling were obtained by Galerkin method. The equations were solved by finite difference method. The effects of impact velocity, lamination angle, initial geometric imperfection on the axial dynamic buckling of laminated composite cylindrical shells were discussed.

由Hamilton原理导出包含初始几何缺陷的复合材料层合圆柱壳的非线性动力方程；将横向位移设为对称及非对称两部分，由Galerkin方法得到以位移形式表达的动力屈曲控制方程，通过有限差分方法求解；讨论了冲击速度、铺层角度、初始几何缺陷等各种因素对复合材料圆柱壳轴向冲击动力屈曲可能产生的影响。

The buckling numerical analysis was made to the rod which is hinge joint and uniform cross section under the axial dynamic loading,basing on the finite element theory.

阐述了动力屈曲分析的Ansys/Ls-dyna有限元理论，基于该有限元程序对两端铰接、等截面直杆在轴向动力载荷作用下的屈曲过程进行了数值模拟和分析。

This thesis contains three parts: The first part focused on the simulation of the dynamic buckling for rod impacted by dynamic force and rigid body in axial direction, which is hinge joint and uniform cross section, basing on the ANSYS/LS-DYNA and PAMCRASH.

本文的研究工作主要有三部分组成：第一部分基于有限元程序ANSYS/LS-DYNA、PAMCRASH分别对两端铰接、等截面直杆在轴向动力载荷作用下的屈曲和刚性块轴向冲击作用下直杆的动力屈曲过程进行了数值模拟和分析。

This device consists of two oblique micro-beams with an inertial mass in the middle.

利用倾斜支撑微梁结构大挠度后屈曲的非线性横向刚度，设计了一种新型屈曲式微机械加速度开关。

The discrete stiffener solution and orthotropic plate solution are used for analyzing the buckling behavior of intermediately stiffened plates theoretically in this paper. Thus, closed-form solution of critical buckling stress and required adequate stiffening rigidity of the stiffener is obtained.

本文分别用分离加劲肋法和各向异性板法对纵向中间加劲板件的屈曲性能进行了理论分析，得到了屈曲应力和理论充分加劲刚度解析表达式。

This equation is changed into the standard form of the Mathieu equation by using Galerkin method.

应用Galerkin原理将该屈曲方程整理为Mathieu方程的标准形式，并利用Mathieu方程解的稳定区域与非稳定区域的分界，即方程系数的本征值关系，得出磁弹性问题屈曲临界状态的判别方程。

The criterion equation of the magnetic-elasticity kinetic problem has been derived by the determination on the boundary line of steady and unsteady solution area of Mathieu equation, i.e.

通过具体算例，给出四边简支矩形板的磁弹性动力屈曲方程以及屈曲临界状态与相关参量之间的关系曲线，并对计算结果及其变化规律进行分析讨论。

Do not gum up the work by telling mother what we are going to do .

别告诉母亲我们要干的事，那会把事情搞糟的。

In recent years, application of the partial prestressed concrete beam s is developed.

近年来，随着部分预应力砼梁应用的推广，发现我国规范所采用的名义拉应力法的计算结果不稳定。