文档介绍：土木工程专业英语
ENGLISH FOR CIVIL ENGINEERING
讲解班级:101115
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He is really somebody. -- My uncle has 1000 men under him. -- He is really somebody. What does he do? -- A maintenance man in a cemetery.
LESSON 8 FORCE METHOD OF STRUCTURAL ANALYSIS (力法的结构分析)
Introduction:
Force method of analysis is one of the basic methods of analysis of structures。 It is proposed to outline the primary procedure in this paper.
(力法的分析是一种基本的结构分析方法,在这篇论文中讲述了其主要的分析过程)
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Description of method
First of all,the degree of statical indeterminacy is determined.
(超静定的次数是起决定因素的)
A number of releases equal to the gegree of indeterminacy is now introduced, each release being made by the removal of an external or an internal force.
(去掉的多余约束等于现在介绍的超静定的次数,每个去掉的多余约束由移去的内力或外力所决定)
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The released introduce inconsistencies in displacements,and as a second
step these inconsistencies or
"errors" in the released
structure are determined.
(第二步,释放所引起的位移是不一样的,
这些变形或偏差在放松结构是已经决定的)
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The third step consists of
a determination of the
displacements in the
released structure due to unit
values of the redundancies.
(第三步,主要讲的是在单位力作用下,在基本结构上的相应位移。
在相同的位置和相同方向上的位移要求与第二步中相应位移的偏差时一样的)
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Hence,we find the forces on the original indeterminate structure:they are the sum of the correction forces(redundancies) and forceson the released structure) (因此,我们找到作用于最初的超静定结构上的力:它们是赘余力和作用在基本结构上的力的和。)
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The structure is statically indeterminate to the second degree,so that two redundant forces have to be removed. (这个结构是二次超静定的,因此有两个多余的约束力必须去掉)
The moment and the vertical rection at C
The vertical reactions at A and B
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Remove the vertical recation at B and the moment at C. The released structure is then a simple beam AC with redundant forces and displacements as shown in -1b.
Example 8-1
-1a shows a beam ABC fixed at C,resting on roller supports at A and B,and carrying a uniform load of q per unit length.
The beam has a constant flexural rigidity