文章目录

• 前言
• 一、简单示例
• 二、gismo-3维IGA
• • 3维程序中的几何模型
• 三、xml文件的理解
• • 1、xml文件示例
  • 2、gismo中二维示例文件-一个曲面（简单）
• 四、三维程序中xml文件的理解
• • 三维几何模型
  • 边界信息
• 五、三维程序运行
• • 细化四次
  • 细化5次
• 总结 #pic_center

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前言

只是为方便学习，不做其他用途！

一、简单示例

参考网页 Tutorial 02: Geometry

#include <gismo.h>using namespace gismo;int main(int, char**){gsInfo.precision(3);gsKnotVector<> kv(-1, 0, 3, 3, 1);gsBSplineBasis<> bsp(kv);gsInfo << bsp.detail() << "\n";bsp.uniformRefine();gsInfo << bsp.detail() << "\n";return 0;}

二、gismo-3维IGA

运行代码需要配置好gismo环境
还需要将 terrific.xml 放在项目文件下，和cpp文件放在同一文件路径下

/// This is an example of using the linear elasticity solver on a 3D multi-patch geometry./// The problems is part of the EU project "Terrific".////// Authors: O. Weeger (2012-1015, TU Kaiserslautern),/// A.Shamanskiy (2016 - ...., TU Kaiserslautern)#include <gismo.h>#include <gsElasticity/gsElasticityAssembler.h>#include <gsElasticity/gsWriteParaviewMultiPhysics.h>#include <gsElasticity/gsGeoUtils.h>using namespace gismo;int main(int argc, char* argv[]){gsInfo << "Testing the linear elasticity solver in 3D-线弹性求解器的三维测试.\n";//=============================================================//// Input ////=============================================================////std::string filename("terrific.xml");//初始数据文件std::string filename("test.xml");//初始数据文件real_t youngsModulus = 74e9;//杨氏模量real_t poissonsRatio = 0.33;//泊松比index_t numUniRef = 0;//节点插入数index_t numDegElev = 0;//升阶次数index_t numPlotPoints = 10000;//preview软件画图的点数量// minimalistic user interface for terminal 终端最简用户界面gsCmdLine cmd("Testing the linear elasticity solver in 3D.");// 定义一个gsCmdLine类 命名为cmdcmd.addInt("r", "refine", "Number of uniform refinement application", numUniRef);cmd.addInt("d", "degelev", "Number of degree elevation application", numDegElev);cmd.addInt("p", "points", "Number of points to plot to Paraview", numPlotPoints);try { cmd.getValues(argc, argv); } // 不太用看 不知道这个命令代表啥catch (int rv) { return rv; }//=====================================================================//// Scanning geometry and creating bases:扫描几何和创建基函数 ////=====================================================================//// scanning geometry 扫描几何gsMultiPatch<> geometry; // 定义一个多片gsReadFile<>(filename, geometry);// 将plateWithHole.xml文件中的数据赋值给 geometry// creating basis 生成基函数gsMultiBasis<> basis(geometry);for (index_t i = 0; i < numDegElev; ++i) // 升阶次数basis.degreeElevate();for (index_t i = 0; i < numUniRef; ++i) // k细化（节点插入）次数basis.uniformRefine();gsInfo << basis ;//=====================================================================//// Setting loads and boundary conditions 设置载荷和边界条件 ////=====================================================================//// source function, rhs 源函数？-解析解？gsConstantFunction<> f(0., 0., 0., 3);// surface load, neumann BC 黎曼边界对应载荷边界条件 荷载BC 力的边界条件gsConstantFunction<> g(20e6, -14e6, 0, 3);// boundary conditions 边界条件 黎曼边界对应载荷边界条件 dirichlete对应位移边界条件gsBoundaryConditions<> bcInfo;// Dirichlet BC are imposed separately for every component (coordinate) 对每个分量(坐标)分别施加 Dirichlet BCfor (index_t d = 0; d < 3; d++){bcInfo.addCondition(0, boundary::back, condition_type::dirichlet, 0, d);/* bcInfo.addCondition(1, boundary::back, condition_type::dirichlet, 0, d);bcInfo.addCondition(2, boundary::south, condition_type::dirichlet, 0, d);*/}// Neumann BC are imposed as one function 将 Neumann BC 作为一个函数bcInfo.addCondition(0, boundary::front, condition_type::neumann, &g);//bcInfo.addCondition(14, boundary::north, condition_type::neumann, &g);//=====================================================================//// Assembling & solving ////=====================================================================//// creating assembler 创建刚度矩阵?gsElasticityAssembler<real_t> assembler(geometry, basis, bcInfo, f);assembler.options().setReal("YoungsModulus", youngsModulus);assembler.options().setReal("PoissonsRatio", poissonsRatio);assembler.options().setInt("DirichletValues", dirichlet::l2Projection);gsInfo << "Assembling...\n";gsStopwatch clock;clock.restart();assembler.assemble();gsInfo << "Assembled a system with "<< assembler.numDofs() << " dofs in " << clock.stop() << "s.\n";gsInfo << "Solving...\n";clock.restart();#ifdef GISMO_WITH_PARDISOgsSparseSolver<>::PardisoLDLT solver(assembler.matrix());gsVector<> solVector = solver.solve(assembler.rhs());gsInfo << "Solved the system with PardisoLDLT solver in " << clock.stop() << "s.\n";#elsegsSparseSolver<>::SimplicialLDLT solver(assembler.matrix());gsVector<> solVector = solver.solve(assembler.rhs());gsInfo << "Solved the system with EigenLDLT solver in " << clock.stop() << "s.\n";#endif//=====================================================================//// Output ////=====================================================================//// constructing solution as an IGA functiongsMultiPatch<> solution;assembler.constructSolution(solVector, assembler.allFixedDofs(), solution);// constructing stressesgsPiecewiseFunction<> stresses;assembler.constructCauchyStresses(solution, stresses, stress_components::von_mises);if (numPlotPoints > 0){// constructing an IGA field (geometry + solution)gsField<> solutionField(assembler.patches(), solution);gsField<> stressField(assembler.patches(), stresses, true);// creating a container to plot all fields to one Paraview filestd::map<std::string, const gsField<>*> fields;fields["Deformation"] = &solutionField;fields["von Mises"] = &stressField;gsWriteParaviewMultiPhysics(fields, "test_le", numPlotPoints);gsInfo << "Open \"test_le.pvd\" in Paraview for visualization.\n";}return 0;}

3维程序中的几何模型

三、xml文件的理解

1、xml文件示例

网址https://gismo.github.io/Tutorial02.html

2、gismo中二维示例文件-一个曲面（简单）

可以参考之前的博客gismo中用等几何解决线弹性问题的程序示例来理解xml文件

注： 一个平面没有 interfaces这一项
对 interfaces这一项 目前还没有理解

四、三维程序中xml文件的理解

三维几何模型

边界信息

给的示例文件中有15个体组装在一起

五、三维程序运行

细化四次

运行时间：14分钟

细化5次

运行时间：4.58h
组总刚：1.6h
解方程组：2.98h

总结 #pic_center

空格         空格

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二维数

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