Measurement method of residual compression strength of composite material laminated board containing impact damages

Abstract

The invention belongs to a composite material technology and relates to a measurement method of residual compression strength of a composite material laminated board containing impact damages. The measurement method comprises the following steps of: carrying out ultrasonic C scanning nondestructive testing on the impacted surface of the composite material laminated board containing the impact damages; then, establishing a finite element model which is the same as the composite material laminated board in shape and is the same as a compression destructive test in boundary conditions; inputting nondestructive testing information into the finite element model and multiplying one reduction factor R(j) by an elastic constant of a material containing a damage paved layer, so as to reach functions of softening materials and reducing the bearing capability; and finally, calculating the finite element model to obtain the residual compression strength value. The measurement method disclosed by the invention can really reflect damage distribution conditions of each layer, can conveniently establish a model and has a fast calculation speed, so that the measurement method has a great actual application value.

Description

technical field [0001] The invention belongs to composite material technology, and relates to a method for measuring and calculating the remaining compressive strength of composite material laminates with impact damage. Background technique [0002] Literature [Hiroshi Suemasu, Wataru Sasaki. A Numerical Study on Compressive Behavior of Composite Plates with Multiple Circular Delaminations Considering Delamination Propagation [J]. Composite Science and Technology, 2008, 68(12): 2562-2567.] is a typical representative Current method for estimating residual compressive strength of composite laminates with impact damage. The method is calculated by establishing a finite element model method. The specific method is: [0003] 1) According to the assumed delamination damage, the laminate is divided into several sub-layers. Each sub-layer is simulated with a solid element; [0004] 2) Use cohesive element or virtual crack closure technique (Virtual Crack Closure Technique, VCCT...

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Problems solved by technology

[0007] 1) The delamination damage caused by impact exists almost between any two adjacent plies, and the shape is irregular

It is very difficult to simulate these delamination damages in finite element models;

[0008] 2) The impact damage is simulated at the assumed position inside the laminate model, which is very different from the actual delamination damage, which affects the credibility of the calculation results;

[0009] 3) The finite element model established according to this method needs to consider geometric nonlinearity, structural stability, contact problems and damage expansion at the same time, which makes it difficult to converge the calculation results and the calculation is not easy to succeed

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