qx~n/l~n Study on area and position of mass center in bending moment diagram under load

The basic way that verifies whether bending moment diagram is correct is derivative judge.

The bending deformation is one of the most important deformations in the engineering, analysis of internal bending forces is the key for knowing the bending deformation, the internal bending forces include two factors of the shear and bending moment, and to draw the internal bending force diagram is to draw the shear diagram and bending moment diagram.

A rapid design method to determine the amount of prestressing tendons and reinforcements in frame beam using moment diagram is proposed in this paper, which can be used efficiently in the primary design stage.

Superposing is one of methods to obtain the sheer diagram and moment diagram of general beams that bear complicated loads, the essay details superposing which is a direct available method , and focuses application of superposing on the sheer diagram and moment diagram of beam such as mirror image symmetry.

In this article,the basic principles and general methods for drawing the shear diagram and bending moment diagram by the relations of derivative among shear force,bending moment and density of external distributed load have been analyzed mostly.

There exist some insufficiency in the analysis of general bending moment figure in the materials mechanics textbooks adopted in many colleges.

It is sitting up Three-columniation End Moment Equation in Frame by analyses three spans pole end moment and its parameter bending moment diagram with moment equilibrium at joint and compatibility of displacement.

In the meantime,it can complete the approximate calculation of maximum bending moment and drawing of envelope of bending moment on simply supported beam by the action of both permanent loads and moving boads.