基于LM算法的粘弹性材料剪切松弛模量的拟合

发布时间：2018-03-21 12:09

  本文选题：固体力学　切入点：LM算法　出处：《材料导报》2017年S1期 　论文类型：期刊论文

【摘要】：在对粘弹性材料进行有限元计算时,需要材料的剪切松弛模量,必须对经验公式或实验数据进行转换。根据KWW经验公式与广义Maxwell剪切松弛函数的对应关系,列出了求解松弛时间与剪切松弛模量的超定非线性方程组,用LM优化算法得到了方程组的最优解。初步讨论了初值的选取方法。根据此方法得到的松弛时间与剪切松弛模量的拟合曲线的拟合度达到了0.99以上。所提出的方法也适用于用实验数据(随时间变化的应力应变)求解材料的剪切松弛模量。
[Abstract]:In the finite element calculation of viscoelastic materials, the shear relaxation modulus of the material is required, and the empirical formula or experimental data must be converted. According to the corresponding relation between the KWW empirical formula and the generalized Maxwell shear relaxation function, The overdetermined nonlinear equations for solving relaxation time and shear relaxation modulus are given. The optimal solution of equations is obtained by using LM optimization algorithm. The method of selecting initial value is discussed. The fitting degree of the curve between relaxation time and shear relaxation modulus obtained by this method is above 0.99. The method can also be used to calculate the shear relaxation modulus of materials using experimental data (stress and strain varying with time).
【作者单位】： 清华大学深圳研究生院;
【基金】：国家863计划项目(2015AA043302) 深圳市基础研究项目(JCYJ20150529164918737)
【分类号】：TB301
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本文编号：1643792