Method for predicting bending response of simply supported reinforced concrete beam under near-field explosion

Abstract

The invention discloses a method for predicting the bending response of a simply supported reinforced concrete beam under near-field explosion. According to the method, the bending response process ofa structure under near-field explosion can be predicted according to the explosive TNT equivalent, the relative position relation between an explosive and a target and the target characteristic quantity. The method comprises the steps that firstly, a shock wave pressure peak value and specific impulse distribution model of the structure surface is established according to the explosive TNT equivalent and position, then deformation functions and equivalent conversion coefficients of elastic and plastic stages are calculated according to load characteristics, and a single-degree-of-freedom kinetic equation of the structure under near-field explosion is established; and finally, the bending response of the structure can be predicted through equation difference solution.

Description

technical field [0001] The invention belongs to the field of damage evaluation, and mainly relates to a method for predicting the bending response of a simply supported reinforced concrete beam under near-field explosion. Background technique [0002] The equivalent single degree of freedom method is a method that can simplify the continuous beam structure under uniform load into a single degree of freedom dynamic system under concentrated load based on the principle of energy conservation. This method is widely used because of its convenient and fast calculation. Applied to the prediction of the bending response of reinforced concrete beams under uniform blast loads. [0003] The book "Structural Dynamics" published by Professor Biggs in 1964 introduced in detail the equivalent single-degree-of-freedom model of reinforced concrete beams under uniform explosion loads, and gave the calculation methods for many parameters in the model. Later, in the TM5-1300 manual jointly pu...

AI Technical Summary

Problems solved by technology

[0006] First: Under the action of non-uniform load, the deformation function of the deflection line of the structure will change, and the difference in the deformation function will not only change the critical point of the structure entering the plastic state, but also affect the resistance of the structure; and the above methods have not considered to the difference in structural deformation functions under non-uniform loading;

[0007] Second: The impact of non-uniform load on the bending resistance of the structure is related to the deformation function and the non-uniformity of the load at the same time, which is not fully considered in the above models;

[0008] Third: In the iterative calculation of the single-degree-of-freedom model, the structural resistance is closely related to the deformation rate. The dynamic deformation rate will cause the dynamic material strain rate, which will make the material strength change dynamically and then change the bending resistance. However, the above models use a constant strain rate enhancement factor;

[0009] Fourth: The above model fails to fully consider the shape hole and non-uniform load characteristics when calculating the mass conversion coefficient and load conversion coefficient

Images