1、 Elasticity12Chapter 1 Introduction1-1 The Modeling of the Engineering Mechanics Problem1-3 The Basic Assumption of the Elasticity Problem1-4 The Several Basic Concepts of Elasticity1-5 The Study Method of the Elasticity1-2 The Basic Contents of the ElasticityExercises Lesson3第一章 绪 论1-1 工程力学问题的建模1-3
2、 弹性力学问题的基本假设1-4 弹性力学中的几个基本概念1-5 弹性力学的学习方法1-2 弹性力学的基本内容习题课4The elasticity is a branch of the solid mechanics, the task of it is to research the elasticity objects stress, deformation and displacement due to external force or change of temperature.The elasticity is the foundation of studying plasticit
3、y, fracture mechanics and finite element method.This course shows the mathematics modeling process of mechanics problems completely, and establishes the basic equation and boundary condition of the elasticity and proceeds to beg the solutions of some problem. The foundation of the elasticity basic e
4、quation lays a foundation for further number method.5弹性力学是固体力学的一个分支，研究弹性体由于外力作用或温度改变等原因而发生的应力、形变和位移。弹性力学是学习塑性力学、断裂力学、有限元方法的基础。本课程较为完整的表现了力学问题的数学建模过程，建立了弹性力学的基本方程和边值条件，并对一些问题进行了求解。弹性力学基本方程的建立为进一步的数值方法奠定了基础。6Through the process of establishing the mechanics model in the engineering mechanics problem,
5、generally three parts should be simplified:Suffering Force Simplification Material SimplificationConstruction Simplification1、 The Modeling Process of the Engineering Mechanics Problem1-1 The Modeling of theEngineering Mechanics ProblemFig.1-1 7工程力学问题建立力学模型的过程中，一般要对三方面进行简化：受力简化材料简化结构简化一、工程力学问题的建模过程1
6、-1 工程力学问题的建模图 1-1 8Material is simplified according to these hypothesises of the same kind, consecution and uniformity in each direction. （ 3） Material simplificationAccording to the Saint-Venants principle, the complex force system is simplified to an equivalent force system.（ 2） Suffering Force SimplificationSuch as space problem is simplified to flat surface problem and symmetry problem in axis, and entity construction is simplified to plate construction（ 1） Construction Simplification9根据各向同性、连续、均匀等假设进行简化。 （ 3）材料简化根据圣维南原理，复杂力系简化为等效力系。（ 2）受力简化如空间问题向平面问题的简化，向轴对称问题的简化，实体结构向板、壳结构的简化。（ 1）结构简化10
