摘要
平稳随机过程数值仿真分析因结构高度非线性因素而成为平稳随机振动分析中的难点,通常采用振型叠加法,将非线性结构简化为线性结构进行平稳随机过程数值仿真分析。为克服这一难点,文中以某一非线性预应力结构为例,首先采用谐波叠加法,将已知的频域内功率谱密度曲线转化为时域内的加速度曲线,然后通过中心差分法,对非线性结构进行平稳随机过程数值仿真分析,并对数值仿真分析中存在的关键性技术进行探讨。结果表明,对具有预应力的非线性结构,振型叠加法在一定程度上能够反映结构的动力学特性,但不能反映结构的非线性特性,而中心差分法能更精确地反映非线性结构在随机激励下的动力学特性。通过分析,文中针对非线性结构平稳随机过程数值仿真分析,提出一种综合振型叠加法和中心差分法的有限元分析方法,目的在于解决平稳随机过程数值仿真分析中结构的高度非线性因素,为高度非线性预应力结构的平稳随机过程数值仿真分析提供一种新思路。
The difficuhy of numerical simulation analysis of stationary random vibrations on nonlinear structure is a nonlinear process. Conventionally, by mode superposition method the nonlinear model is simplified as linear model. For this problem, a nonlinear prestress structure is taken as an example. Firstly, harmony superposition method is applied to transform known power spectral density curve into acceleration curve; secondly, according to center difference method, numerical simulation analysis of a computer＇s example has been studied; lastly, key technique is studied. The result of simulation indicates that for nonlinear prestress structure mode superposition method can reflect dynamic characteristics of structure in some extent and can＇ t reflect nonlinear characteristics. But center difference method can accurately reflect nonlinear dynamic characteristics of prestress structure. By analyzing this paper puts forwards a new method integrated analysis of mode superposition method and center difference method for numerical simulation analysis of stationary random vibrations on nonlinear structure. The purpose is to solve the difficulty of nonlinear process and supply more a new method for numerical simulation analysis of stationary random vibrations for nonlinear prestress structure.
出处
《机械强度》
EI
CAS
CSCD
北大核心
2008年第4期523-528,共6页
Journal of Mechanical Strength
关键词
随机振动
非线性结构
预应力
数值仿真分析
Random vibration
Nonlinear structure
Prestress
Numerical simulation analysis
