结构力学英文课件 Chapter1.pptVIP

2. Simplification of Joints When the members are connected together, the mutual displacements of the members are restrained. The connection point is called joint .There are two types joint. ① Hinge Joint. (Small resistance in bending) A hinge joint restrains the translation of one member relative to the others , the members can have independent free rotations about the centre of the hinge ② Rigid Joint The members form a monolithic body, they can move and translate as a group, but can not move with respect to each other. Introduction Introduction ③ Combination Joint A B C D E F G A：Rigid joint B、D：Hinge joint C：Combination joint BF、CD Hinge joint， BC、CF Rigid joint 3. Simplification of supports ① Link support ② Hinge Support Introduction ③ Fixed support ④ Fixed direction support (定向支座) Introduction A MA VA HA 4、Simplification of load （1）Body load：body load can be simplified as line-load. Dead load, for instance. （2）surface load：surface load can be simplified as concentrated load or line load。For example, wind, snow load, and equipment. Introduction 1.2 Classification of structures ① in dimensions domain : Structures can be classified into plane stru. And space stru. If members of the stru. are in a plane, its loads are also in the same plane .It is called plenary stru. If members are not in a plane or its loads are not lie in the same plane Introduction ② In Restraints Statically determinate stru. Statically indeterminate stru. Unstable stru. Introduction Introduction 1.3 Plenary framed structures Plenary framed structures can be divided into the following forms 梁 拱 桁架 刚架 组合结构 (1)、beam (2)、arch (3)、truss (4)、rigid frame (5)、composite structure Introduction 1.4 Classifications of loads Duration of application : Dead load: dead load act on structure for ever. Its weight. Dead loads are those whose magnitudes remain constant and whose position doses not change. Live load: live load are those whose ma