Strain_Space

说明：  vumat 本构模型，von mises屈服准则加各向同性硬化准则(vumat von mises constitutive model+isotropic hardening)

Geometrical nonlinear finite element solver

Simpson 求解积分，很方便使用的求解积分的方法。希望大家喜欢(Simpson for integration, it is easy to use solution of the integral approach. I hope you like)

abaqus有限元软件umat（damage）(abaqus finite element software umat (damage))

计算汉克尔函数，包括复数变量和任意阶数。对初学者很有帮助。(Calculate Hankel functions, including complex variable and arbitrary order. Useful for beginners.)

netcdf的fortran接口程序， 利用该程序集，可以非常方便的完成1d-4d netcdf格式的数据的读写

Butterworh滤波器程序,fortran程序，子程序代码很好用，可以根据自己的需求再进行修改。

ABAQUS中用户材料子程序UMAT的开发主要解决两方面的问题：本构模型的建立和积分算法的选择。 本文主要研究非线性材料的UMAT实现方法，并重点研究其迭代算法部分，目前，用户材料子程序UMAT的迭代算法主要是常刚度法，常刚度法的优点在于算法原理较简单，程序编写较方便，缺点是当遇到复杂非线性材料时，其迭代次数较多，收敛速度也较慢，在这个情况下，本文采取的是一种迭代次数较少且收敛速度较快的切线刚度法，具体就是采用FORTRAN语言编制了基于Von-Mises模型的接口程序,并采用切线刚度算法，通过与ABAQUS自带本构关系计算的结果相比较，验证其正确性。(This paper studies the user subroutine UMAT of ABAQUS development methods, the use of FORTRAN language isotropic hardening material model of the interface program, studied the effects of such material is extremely elastic-plastic constitutive relation method. This article UMAT tightly around the secondary development of technology, the first principle of its interface detail, and then for the theory of nonlinear finite element incremental stiffness of the regular tangent stiffness method and the theory of algorithms to do an in-depth analysis of deduced a regular tangent stiffness and rigidity of the law of the specific expression of algorithm theory, and then the preparation of the two algorithms, respectively, of the UMAT program, and finally the establishment of a specific model checking, bringing with ABAQUS elasto-plastic constitutive relation of the calculated results compared to verify the correctness of the two.)

简洁易懂的适合初学者学习的fortran入门教学资料，谭浩强(Simple and easy to understand for beginners to learn fortran introductory teaching materials, Hemopurification)

别人的程序（Fortran）是关于边界元法求解声学问题。(Someone else' s program (Fortran) is on the boundary element method to solve acoustic problems.)