For the uniform state of plane strain shown in the fig ure,which one(s) of the following statement(s) is(are valid?(Assume Poisson's ratio v+0)

We seek to characterize the local state of deformation of the material in a neighborhood of a point P. Consider two points P and Q in the undeformed

The following expression is the right statement of linear momentum balance for a deforming body of an arbitrary material

A Cauchy stress component at a given(fixed) point P of a structure in equilibrium under the action of external loads is defined when 1. the direction of the face on which the stress component acts is specified 2 the direction of the force from which the stress component is derived is specified None of the above statements

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

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

早在英国爱德华二世(1284~1327)年代,这位国王就曾想通过禁止使用煤来解决 燃煤产生的烟气污染问题。他曾颁布了一道法令:“无论是谁被发现燃烧煤,他就是 有罪的,都将受到杀头的惩罚”。由此可见,大气污染自古有之。如同其它污染控制 样,大气污染控制技术和工程、设备也是在大气污染到了一定的程度、顺应时代需 要的产物:控制技术的研究与工程应用的主要推动原因是严重的大气污染事件的刺 美国的 Donora是一座钢铁小城,在1948年仅有3家主要工厂:钢铁厂、电线厂 和锌板厂

采用关联模型比较典型的案例是“尿布与啤酒” 的故事。在美国,一些年轻的父亲下班后经常 要到超市去买婴儿尿布,超市也因此发现了 个规律,在购买婴儿尿布的年轻父亲们中,有 30%~40%的人同时要买一些啤酒。超市随后 调整了货架的摆放,把尿布和啤酒放在一起, 明显增加了销售额。同样的,我们还可以根据 关联规则在商品销售方面做各种促销活动

Introduction to Engineering Heat Transfer These notes provide an introduction to engineering heat transfer. Heat transfer processes set limits to the performance of aerospace components and systems and the subject is one of an enormous range of application. The notes are intended to describe the three types of heat transfer and provide basic tools to enable the readers to estimate the magnitude of heat transfer rates in realistic aerospace

Part 2.: introduction to thermochemistry SB&VW-14.1-14.6 Until now, we have specified the heat given to the devices analyzed, and not concerned ourselves with how this heat might be produced. In this section, we examine the issue of how obtain the heat needed for work