The state of stress at a point is completely determined when: 1. the stress vectors on three different planes are specified 2. the stress vectors on two different planes are speciale 3. the stress vectors one arbitrary plane is spec-

16.21 Techniques of Structural Analysis and sig Spring 2003 Unit #1 In this course we are going to focus on energy and variational methods for structural analysis. To understand the overall approach we start by con- trasting it with the alternative vector mechanics approach

which generalizes to the statement. This reduces the number of material constants from 81 to 54. In a similar fashion we can make use of the symmetry of the strain tensor This further reduces the number of material constants to 36. To further reduce the number of material constants consider the conclusion from the first law for elastic materials, equation

1.掌握材料在轴向拉压时的力学性能。 2.掌握材料在常温静载作用下三种强度失效准则及其应用:最大切应力准则,奇变能密度准则,最大拉应力准则

Strain energy and potential energy of a beam brec sedans hoMe the neutra xxis remain So Figure 1: Kinematic assumptions for a beam Kinematic assumptions for a beam: From the figure: AA'=u3(a1) Assume small deflections: B B\,BB\=3+ duy

We are going to consider the forces exerted on a material. These can be external or internal. External forces come in two flavors: body forces(given per unit mass or volume) and surface forces(given per unit area). If we cut a body of material in equilibrium under a set of external forces along a plane as shown in fig. 1. and consider one side of it we draw two conclusions: 1 the equilibrium provided by the loads from the side taken out is provided by a set of forces that are distributed among the material particles adjacent to

The work of the external forces in the spring system of the figure is given by W=B*(U1+U2+U3)(2) W=P1*U1+P2米U2+B米U3(3) None of the above statements

10.1 组合逻辑电路的分析与设计 10.2 组合逻辑部件 10.3 竞争与冒险

第3章电子商务系统的规划 3.1概述 3.2电子商务系统规划的内容 3.3电子商务战略规划 3.4电子商务系统规划 3.5电子商务系统的规划报告

1、实验准备及常规仪器设备使用 2、分立元件及负反馈放大电路设计 3、运放基本应用电路 4、测量放大器 5、晶体管输出特性曲线测试电路 6、LC三点式振荡器 7、模拟乘法器及调幅与检波电路