Numerical Study On Crashworthiness Of Civil Aircraft Composite Structure

The crashworthiness design and certification of aircraft structures is confronted with significant challenges due to the application of composite materials over the coming years. Both engineering experience and much experimental verification have been mainly depended on in crashworthiness design of composite structures for a long time. It has some disadvantages in this method, such as long design period, high costs and poor reproducibility and so on. With the development of the commercial finite element software, it is becoming a practicable and effective approach that adopting the method of numerical simulation combined with fewer experimental tests. Therefore, it is a significant work that researches the numerical simulation method of composite structures in crashworthiness.As a background of composite aircraft structures crashworthiness design, the applicability of MAT 54 material model in crashworthiness simulation of composite structures is analyzed, the energy absorption characteristics of composite tubes and aluminum-composite hybrid tubes also are researched based on FEM numerical simulation. The main contents are listed as follows:(1) It takes T700/2510 composite sinusoidal specimen on as the object of the research, creates model of the quasi-static crushing. The sensitivity of simulation to MAT54 material model parameters is analyzed. The suitability of material model to simulate the crashworthiness of composite structure is evaluated.(2) The double-shells elements FEM model for the quasi-static crushing simulation of T700/QY8911 composite circular tube is created. Compare results of simulation to experimental test data on quasi-static collapse, and verify the method of model building. The energy absorption characteristics of composite tubes with typical section shapes are analyzed comparatively in the conditions of quasi-static collapse and crash events. The energy absorption capability of composite tubes which have different section shapes is evaluated synthetically.(3) The energy absorption characteristics of aluminum-composite hybrid tubes are researched based on FEM numerical simulation. The accurate finite element simulation model is obtained through comparing results of simulation to experimental test data, and then the influence of the section shapes, trigger, composite ply angle and load condition on energy absorption characteristics of aluminum-composite hybrid tubes is studied.