autodyn之状态方程(EOS)

原来的blog数据丢了，幸好还有百度快照，哈哈。

Autodyn v6.1的Theory Manual，目前无法用到完整正式版，但手册还是可以看的。这里顺便做个笔记，详细原理当然还是要参考相关理论书籍了。Autodyn便利之一就是有一个庞大的材料库。

什么是状态方程(Equation of State)：Then the relation between the hydrostatic pressure, the local density (or specific volume) and local specific energy (or temperature) is known as an equation of state.通常也就是下面的格式：

p = f (v, e)

Autodyn 中讨论时进行了简化：in the following sections, viscosity, heat conduction and deviation of the medium from thermodynamic equilibrium (at any instant and any point) will be neglected.

下面就是一些状态方程的形式和不同使用范围：

１.Ideal Gas Form

形式：pv＝RT

比较重要的是绝热指数：the adiabatic exponent γ is a constant (equal to 1 + R / c_v).

注意事项： Solutions with this simple equation of state should therefore be viewed critically when run to very long times or very large expansions

２.Linear Equation of State

形式：p=Kμ

where μ = (ρ/ρ₀) - 1, and K is the material bulk modulus

适用：In many cases, especially if the material is a liquid or solid, the influence of changes in entropy is small or negligible so that p may be considered a function of density (or specific volume) alone.

注意事项：This form of equation of state is of use only for fairly small compressions and should not be used if it is considered that large compressions may occur.

３.Mie-Gruneisen Form

形式：省略。

手册中没有多说，以后参考理论书籍。

4.Polynomial Equation of State

形式：

For μ > 0 (compression):

P=A₁μ+A₂μ²+A₃μ³+(B₀+B₁μ) ρ₀e

For μ < 0 (tension):

P=T₁μ+T₂μ²+B₀ρ₀e

说明：This is a general form of the Mie-Gruneisen form of equation of state and it has different analytic forms for states of compression and tension.

范围：This is probably true as long as the range in density variation (and hence range in μ) is not too large.

５.The “Shock” Equation of State

形式：U=c₀+sup

适用范围： for most solids and many liquids over a wide range of pressure there is an empirical linear relationship between these two variables.算是冲击计算最经典的状态议程了。

注意： At high shock strengths some nonlinearity in this relationship is apparent, particularly for non-metallics. 因此Autodyn还提供了别的形式，比如二次形式。

6.Expansion Equations of State

略。自己看的也不仔细。

7.Tillotson Equation of State

形式：对不同的区域有不同的形式。略

适用范围：provide an accurate description of the material behavior of metallic elements over the very wide ranges of pressure and density met in hypervelocity phenomena.

压力范围也是相当广的：The pressure range can be so large that the “low pressure” regime of this form of equation of state is defined as from 0 to 10 Mbar and “high pressure” from 10 to about 1000 Mbar.

It is therefore a very useful form of equation of state to use for general hypervelocity impact problems.

8.Puff Equation of State

形式：对应三个区域，分别有三个等式。

适用范围：Like the Tillotson formulation above this equation of state was constructed to cover the behavior of material from cold shocked regions to hot, highly expanded regions.

9.Two-Phase Equation of State

适用范围：in which liquid and vapor co-exist)

10.Sesame equation of state

适用范围：较广，且允许when materials undergo phase changes。The Sesame EOS has been extensively used for aluminium hypervelocity impact simulations at Century Dynamics . This work used the Lagrange and SPH processors. Use of this EOS with the Euler processor is as yet unproven.

使用注意：不允许用户改变参数。

autodyn之状态方程(EOS)相关推荐

FCC单晶塑性abaqus-vumat
FCC单晶塑性abaqus-vumat 0. 整体思路 1. 弹性各向同性 2. 12个滑移系 3. 旋转 4. 率相关的滑移硬化本构 5. 求解12个滑移量 6. 应力更新 7. 更新状态变量 8. ...
AutoDYN学习笔记---Part_1
AUTODYN软件学习笔记前言软件使用流程 1. 建立初始化工程 2. 建立模型信息 2.1 材料信息 2.2 初始条件信息 2.3 建立模型数据模型边界条件设定求解设置输出设置总结前言 ...
选择（Ansys2021及以上）Workbench中的LS-DYNA模块，在工程数据库中设置材料参数，选择关键字MAT和EOS
随着Ansys新版本的不断更新,Workbench集成的Ls-dyna模板也在不断完善,在workbench中也能够完成一些Ls-dyna的计算了.那么就介绍一下,在Workbench中,如何在工程数 ...
【系列】EOS开发3 EOS提供的程序和工具
上一篇文章使用了nodeos命令来启动eos服务,这一篇文章,就来介绍一下eos提供的相关程序和工具. nodeos EOSIO的核心守护进程,它可通过插件配置来启动一个节点. cleos 这是一个命 ...
虚拟货币市值回调到4100亿整数关口，EOS逆势站上100关口
虚拟货币虚拟货币市值在过去24小时中,虚拟货币整体回调,市值为4100亿美元.只有EOS逆势上扬,已经站上了100元(17.5美元)上方. 虚拟货币市场距离12月份最高点几乎只有一步之遥. EO ...
区块链 + 大数据：EOS存储
链客,专为开发者而生,有问必答! 此文章来自区块链技术社区,未经允许拒绝转载. 谈到区块链的存储,我们很容易联想到它的链式存储结构,然而区块链从比特币发展到今日当红的EOS,技术形态已经演化了10年之 ...
EOS智能合约：system系统合约源码分析
链客,专为开发者而生,有问必答! 此文章来自区块链技术社区,未经允许拒绝转载. eosio.system 概览笔者使用的IDE是VScode,首先来看eosio.system的源码结构.如下图所示. ...
EOS Cleos 命令使用指南
链客,专为开发者而生,有问必答! 此文章来自区块链技术社区,未经允许拒绝转载. 命令参考操作语法例子获取所有命令 $ cleos 例子获取所有子命令 $ cleos ${command} 例 ...
区块链3.0：拥抱EOS
链客,专为开发者而生,有问必答! 此文章来自区块链技术社区,未经允许拒绝转载. EOS是当下最火的区块链技术,被社会广泛看好为下一代区块链3.0.不同于以太坊的学习,EOS的主语言是C++,本文作为E ...

autodyn之状态方程(EOS)

autodyn之状态方程(EOS)相关推荐

最新文章

热门文章