论文部分内容阅读
在工程设计实践中,经常遇到图(1)的受力模式——单层框架梁上受等距离分布的集中力(如次梁)的作用,需要求出各关键点(A、B、C、D)处的弯矩值,以便画出框架的弯矩图。 但查阅工程力学手册却找不到此模式的有关公式,只有受单个集中力在任意位置作用(图2)及均布荷载作用(图3)的公式。 其实,通过严密的推导,可以求出图(1)情形下各关键点的弯矩力学表达式,而且式子很简洁,很实用,并沟通了图(1〕、(2)、(3)三者的关系,具体方法是,用图(2)的结果来推导图(1),再用图(1)的结果来推导图(3)的结果。通过求极限来推导图(4)、图(5)的结果。
In the engineering design practice, the force pattern of Figure (1) is often encountered - the effect of concentrated forces (such as secondary beams) on an equi-distributed beam on a single-layer frame beam, and the key points (A, B, etc.) need to be found. The bending moment values at C, D) are used to draw the bending moment diagram of the frame. However, consulting the engineering mechanics manual can not find the relevant formula of this model, and only the formula that is affected by a single concentrated force at any position (Figure 2) and uniform load (Figure 3). In fact, through rigorous derivation, the moment-mechanical expressions for the key points in the case of (1) can be found. The equations are very concise, very practical, and communicate with diagrams (1), (2), (3). The specific approach is to use the results of (2) to deduce (1), and then use the results of (1) to deduce the results of (3), and derive the map (4) by Figure (5) results.