摘要
粘弹性材料的本构模型对复合结构的动力分析至关重要,一个精度高、结构简单的本构模型可以使系统分析简单、有效。本文首先采用动态力学热分析仪对一类沥青型阻尼材料进行力学特性测试,得出粘弹性沥青材料的存储模量,损耗模量及损耗因子随频率变化曲线。进而采用一种基于遗传算法(GA)和拟牛顿算法(BFG S)混合算法,对标准流变学模型(STD)、ADF模型以及GHM模型进行了参数优化,结合目标函数的优化结果,分析了各个模型的优缺点。研究表明:(1)GA-BFG S混合算法可以得到精确的全局最优解,且计算量不大,适合于该类问题的求解;(2)对于该类沥青型粘弹性阻尼材料,STD模型,ADF模型可以在较少的待定参数下得到较好的拟合结果;(3)由于ADF模型方便和有限元结合,更适合采用有限元方法对复杂结构分析。参数优化结果为该类阻尼材料的复合结构分析奠定了基础。
Constitutive relation of viscoelastic（VE） materials is vital part for dynamic analysis of compound structure. An exact, simple constitutive relation can make the calculation easy and effective for the whole structure. Firstly, mechanical properties of a type of asphalt materials are tested using Dynamic Mechanical Thermal Analyzer （DMTA）, and curves of storage modulus, loss modulus and loss factor as functions of the frequency are gained experimentally. Then, an approach based on GA-BFGS hybrid algorithm is introduced to determine the parameters in a constitutive relation for viscoelastic materials according to the experimentally obtained material mechanical properties. The standard mechanical （STD）, the ADF, and the GHM models are parametrically optimized. The results show this optimal algorithm is effective for this problem, with a short calculation time. In addition, according to the optimal result of objective function, the advantages and drawbacks of each model are discussed and taken into account to decide an appropriate constitutive relation for this type of damping material. The STD and the ADF model can get good fitting result with few optimal parameters. In view of the virtues of completely compatible with finite element method （FEM）, the ADF model is suitable to analyze complicated structure. This work provides a solid foundation which allows for the analysis of complicated structures involving this damping material.
出处
《振动工程学报》
EI
CSCD
北大核心
2008年第1期84-90,共7页
Journal of Vibration Engineering
基金
国家自然科学基金资助项目(10502032)
高等学校学科创新引智计划资助(B06012)
关键词
粘弹性
本构关系
优化
GA-BFGS混合算法
viscoelasticity；constitutive relation；optimization；GA-BFGS hybrid algorithm
