Three methods of unit impulse response in time domain are presented,odd function balance,equal initial condition and linear system analysis.

First, introduces a new application of odd function method in the plasticity limit analysis.

Using program of singular function to calculate internal forces of bending pole;

There is a mistake about singular function calculation in the book of "Electric Circuit",which is widely used as the textbook by many colleges.

By means of singular functions, the equations of moment, torque and bending section modulus are given and the general expressions are derived for calculating the torsional stress, angle and deflection of the shaft under complex loads.

Method of establishing the deflection curve of a beam by singularity functions;

Study of the elastic mechanics problem in narrow rectanglar girder by the singularity function;

Based on the improved story analysis model that is used to be widespread, the author sets up a new model with rigid-suspended-joints in core-tube suspended structure, and deduces flank-displacement rigidity matrix used singularity function.