任意铺设纤维增强型层合板非线性弯曲的基本方程

利用变分原理,在Reddy高阶横向剪切变形理论基础上,建立了任意铺设纤维增强型层合板非线性弯曲的基本方程,该方程具有普遍性。由所建立的方程,计算了在均布载荷作用下,对称角铺设及正交铺设均质各向异性矩形叠层板在不同边界条件下非线性弯曲的解析解,并针对给定材料进行了数值计算。     

用变分原理推导复合材料薄层合板的非线性弯曲方程

本文应用变分法推导出了由挠度w和平面位移u°、v°表示的任意铺设复合材料层合板的非线性弯曲方程,并讨论了几种特殊铺设层合板的特点以及非线性方程组的应用。     

粘弹性四边松散夹支薄板非线性动力响应

假设泊松比为常数，由Boltzmann叠加原理、非线性几何关系和Karman理论，建立了粘弹性薄板非线性动力方程和四边松散夹支各向同性粘弹性动力弯曲的初边值问题及方程组，并用Galerkin法进行求解，得到动力响应的数值结果。     

复合材料薄壁杆件非线性扭转分析

考虑几何非线性的影响,建立了在拉、压、弯、扭组合变形下复合材料薄壁杆件理论.重点对杆件进行非线性扭转分析.由给出的等效本构方程和总势能泛函,根据最小势能原理导出了所给问题的平衡控制方程和相应边界条件.讨论了该方程和边界条件的求解.     

非线性弹性地基上四边自由矩形薄板的分岔与混沌运动分析

研究了非线性地基上矩形薄板的分岔与混沌运动．运用Hamiltion能量变分原理,建立了非线性弹性地基上四边自由矩形薄板的非线性振动方程．应用分离变量法和Galerkin法对方程进行求解,得到仅以gr（r）为未知函数的Mathieu--Duffing型非线性参数振动方程．在数值分析中,分别对该方程取某一连续变化的参数为变量进行分析,分别作出系统运动的分岔图以及进入混沌运动的庞加莱映射图、相平面轨迹图和时间历程曲线波形图,以揭示地基板系统进入分岔与混沌运动的规律．     

钢纤维混凝土弯曲疲劳性能研究

将钢纤维掺入普通混凝土可以大幅度提高混凝土的抗弯曲疲劳等路用性能,并通过试验建立了钢纤维混凝土的疲劳方程。结果表明,钢纤维不但能使混凝土的强度提高,更主要的是能够显著改善混凝土的韧性,在大应力作用下成倍地提高混凝土的弯曲疲劳寿命。     

对称角铺设矩形层合板大挠度弯曲的摄动解

本文用摄动法求解在横向均布载荷作用下四周刚性夹紧的对称角铺设矩形层合薄板大挠度弯曲问题的近似解.文中绘出了碳环氧 T300/5208组成的规则对称角铺设层合板的挠度-载荷曲线.     

复合材料薄壁杆件非线性扭转分析

考虑几何非线性的影响，建立了在拉、压、弯、扭组合变形下复合材料薄壁杆件理论．重点对杆件进行非线性扭转分析，由给出的等效本构方程和总势能泛函，根据最小势能原理导出了所给问题的平衡控制方程和相应边界条件．讨论了该方程和边界条件的求解．     

冷再生疲劳预估模型的研究

以梁式试件三分点加载弯曲疲劳试验得到的疲劳方程为基础,将材料的容许拉应力引入方程,代替原方程中的参数应力比S,建立σR-logN方程。并通过此疲劳方程对冷再生基层混合料的疲劳性能简要分析。     

开口薄壁杆件振动的弯扭耦合效应

本文建立了开口薄壁杆件弯扭耦合振动方程及方程的解法，通过算例说明，弯扭耦合效应是，扭振为主的频率低于杆扭振频率，弯曲为主的频率高于纯弯曲振动的频率，随着杆截面形心与杆扭转中心距离的增大，弯曲为主的频率与比这一阶频率略高的扭转为主的频率有接受直至重合的趋势。     

双参数地基上弹性矩形板的非线性静力分析

基于能量变分原理,考虑地基耦合效应,建立了双参数地基上弹性板的非线性静力平衡方程.构造了一组满足全部边界条件的试探函数,应用伽辽金法对该组非线性方程进行求解,数值计算中考虑了系统各种参数变化对双参数地基上四边自由矩形板的非线性静力特性的影响.     

Nonlinear Dynamic Analysis of Three Dimensional Flexible Multibody Systems

The nonlinear dynamic problems of three dimensional flexible multibody systems are investigated. The elastic deformation fields of flexible space beams are decomposed into axial deformation and bending deformation, and described by each exact vibration modes in the body coordinate systems. The constrainted nonlinear dynamic equations are derived by using Lagrange multiplier method. A numerical procedure for solving the resulting differential algebraic equations is presented based on Newmark direct integration method combined with the modified Newton-Raphson iterative method. Numerical results verify the effectiveness of the proposed method.     

DQ法求解FGM Levinson梁的静态弯曲问题

基于高阶剪切变形理论,采用微分求积法（DQM）研究了功能梯度材料Levinson梁的静态弯曲解,并与Timoshenko梁的弯曲解进行了比较。考虑功能梯度梁的材料性质沿厚度方向按照幂函数连续变化,建立了梁的无量纲控制方程,给出了均布载荷作用下,长细比为10时,相同尺寸的梁在3种常见的边界条件下功能梯度Levinson梁的无量纲挠度随梯度指数 p的变化规律以及不同边界条件下功能梯度材料Levinson梁的无量纲挠度随长细比的变化规律。     

Numerical Investigation of the Dynamics for Low Tension Marine Cables

This paper presents a numerical investigation into the dynamics of marine cables which are extensively used in offshore industry. In this numerical study, the Euler-Bernoulli beam model is adopted to develop the governing equations of the cable. Bending stiffness is considered to cope with the low tension problem in local area of towing cable, and thus a more accurate solution with the consideration of the axial elongation can be given.The derived strongly-coupled and nonlinear governing equations are solved by a second-order accurate, implicit,and large time step stable central finite difference method. The quadratically convergent Newton-Raphson iteration method is applied to solving the discrete nonlinear algebraic equations. Then a towed array sonar system(TASS)problem is studied. The numerical solutions agree reasonably well with the experimental data and the simulated results of the references. The specified program of the present paper shows great robustness with high efficiency.     

Nonlinear buckling analysis of pre-stressed ring-stiffened circular cylindrical shells under external pressure

This paper is concerned with the nonlinear buckling behavior of pre-stressed ring-stiffened thin circular cylindrical shells under external pressure. According to the geometrical nonlinearity, governing equations are derived by incorporating initial stresses based on Donnell-type shell theory. The “smeared stiffeners” approach is used for ring stiffeners. The numerical analyses are conducted by Gelerkin’s method to obtain critical buckling loads of shells. This study shows effects of initial stresses on stability of shells. Moreover, effects of initial stresses on buckling modes of shells are discussed.     

Steady state analysis of towed marine cables

Efficient numerical schemes were presented for the steady state solutions of towed marine cables. For most of towed systems, the steady state problem can be resolved into two-point boundary-value problem, or initial value problem in some special cases where the initial values are available directly. A new technique was proposed and attempted to solve the two-point boundary-value problem rather than the conventional shooting method due to its algorithm complexity and low efficiency. First, the boundary conditions are transformed into a set of nonlinear governing equations about the initial values, then bisection method is employed to solve these nonlinear equations with the aid of 4th order Runge-Kutta method. In common sense, non-uniform (sheared) current is assumed, which varies in magnitude and direction with depth. The schemes are validated through the DE Zoysa's example, then several numerical examples are also presented to illustrate the numerical schemes.     

参激屈曲梁非线性现象的数值模拟

研究了一端固定一端滑动承受轴向简谐载荷的屈曲梁的非线性振动现象,建立了系统的非线性偏微分控制方程,利用Galerkin法,得到微分动力系统,采用数值模拟研究了系统基本参数共振和主参数共振的两种情况,得到了响应的时间历程及相图,揭示了系统的倍周期分岔、暂态混沌和混沌运动等复杂动力学行为.