一、引言在设计承受移动荷载的结构时,往往要先作出结构的内力包络图。包络图的一般作法是:先作出结构中某指定量值(内力或反力)的影响线,然后按最不利位置摆上移动荷载,求出相应各截面的最大内力值(最大正值和最大负值),最后连以曲线即为所求。简支梁的内力包络图较简单,教材中多有介绍,多跨连续梁也有图表可查;而对于单跨固端梁,则没有现成的图表可借鉴,按常规方法去做也显得繁锁,为了解决这个问题,笔者在理论与实践的结合方面作了一点工作,对单跨固端梁的影响线和内力包络图,编导出一些公式和图表,在此提出供参考。下面介绍公式推导和图表制作过程。 I. INTRODUCTION When designing a structure that is subject to a moving load, it is often necessary to first make an internal force envelope diagram of the structure. The general practice of the envelope diagram is to first make the influence line of a specified magnitude (internal force or reaction force) in the structure, and then move the load according to the most unfavorable position to find the maximum internal force value of each section (the maximum positive value The maximum negative value) is finally determined by the curve. The internal force envelopment diagram of simply supported beam is relatively simple. There are many introductions in the textbooks. There are also charts for multi-span continuous beams. For single-span fixed end beams, there is no ready-made chart for reference. It is also very common to do conventional methods. Lock, in order to solve this problem, the author did a bit of work on the combination of theory and practice, and compiled some formulas and charts for the influence lines and internal force envelope diagrams of single span fixed end beams, which are proposed here for reference. The formula derivation and chart making process are described below.