北京大学：《离散数学》离散数学之二《代数结构与组合数学》第17章 群（5/5）习题课——群的证明

16.1半群与独异点 一、半群、独异点的定义与性质 二、半群与独异点定义 三、半群与独异点性质 四、半群、独异点的子代数、积代数、商代数

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

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-

not repeated in the same additive term where the index appears. Free means that the index represents all the values in its range Latin indices will range from 1 to, (i,j, k

For the potato-shaped body given in class to explain the concept of stress, the field of stress vectors t(n)=t(n)(x)on the plane of normal n given by its cartesian components(1,0, 0) known and its cartesian components are given by the expression

Concept Question Consider the following simple displacement field

16.21 Techniques of Structural Analysis and sig Spring 2003 Unit #4- Thermodynamics Principles First Law of Thermodynamics

Which of the following expressions represents the rate of work done by the stresses during the deformation of a body of an arbitrary material?

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