Optimization method for pretightening force of brittle sandwich structure bolt

Abstract

The invention discloses an optimization method for the pretightening force of a brittle sandwich structure bolt, and belongs to the technical field of mechanical simulation optimization. The method comprises the following steps of: 1, constructing a three-dimensional assembly model of the brittle sandwich structure in finite element software, and defining assembly parameters of the three-dimensional assembly model; 2, applying a pre-tightening force in the model according to a damage critical point to obtain a stress distribution state of a fastening surface; 3, according to stress distribution, the pre-tightening force and the loading sequence of the screws at the angular positions and the side positions are optimized; 4, respectively judging whether the stress distribution after the pre-tightening force optimization and the loading sequence optimization is uniform or not, if so, entering the next step, and otherwise, returning to the step 3 for re-optimization; and 5, outputting an optimal pre-tightening force loading value and an optimal loading sequence. According to the method, the simulation model of the connecting piece is constructed in the connecting process of the brittle sandwich structure, the mapping relation between the fastening torque and the pre-tightening force is constructed through experiments, and finally the effect of optimizing the pre-tightening force of the brittle sandwich structure screw is achieved.

Description

technical field [0001] The invention belongs to the technical field of mechanical simulation optimization, and in particular relates to a method for optimizing the pretightening force of bolts in a brittle sandwich structure. Background technique [0002] In recent years, with the improvement of process technology and simulation testing technology, the research on brittle sandwich materials as structural components has gradually become more and more extensive. Brittle interlayer materials can improve structural bearing capacity, stiffness, redundancy, etc., making them have good development potential. [0003] In the specific engineering example of applying brittle interlayer materials, when threaded fasteners are used to connect brittle interlayers, the size of the brittle interlayer bearing preload often affects the performance of brittle interlayer materials. [0004] Generally, interlayer materials have good ductility and are not sensitive to the pre-tightening force, b...

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Problems solved by technology

[0004] Generally, interlayer materials have good ductility and are not sensitive to the pre-tightening force, but brittle interlayer materials have high hardness and brittleness. During the screw tightening process, excessive pre-tightening force will cause the brittle interlayer to rupture, and too small pre-tightening force will affect the interlayer. airtightness of the structure

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