复合材料机身结构件冲击模拟与吸能特性研究

对具有吸能子地板的全复合材料机身结构进行了垂直向7.9m/s的抗坠毁数值模拟,得到平均加速度、速度及撞击载荷值等动态冲击参数,考虑采用不同的评价方法来评估其抗坠毁特性。并对全复合材料机身结构进行分块设计,考虑在冲击过程中起关键作用的底部结构中加入吸能泡沫,最后利用专业的瞬态动力学软件对有限元设计模型进行了冲击模拟,并与测试结果进行了比较,结果满足抗坠毁设计相应规范要求。计算得到的平均加速度不超过13g,其相对误差不大于11%,撞击载荷最大不超过6kN,坠毁平均负加速度持续时间不超过0.03s,结果较合理。利用本模型可以指导直升机的抗坠毁设计。

Impact simulation and energy absorption characteristics investigation of composite fuselage structures

After the 7.9 m/s vertical drop anti-crash simulation of a full scale composite fuselage structure with energy-absorbing subfloor, the corresponding dynamic impact parameters of the average acceleration, velocity and impact force of the structure were obtained. Different assessment methods were considered to evaluate the crashworthiness characteristics of the structure. The full scale composite fuselage structure was divided into different sections in the design, and the energy-absorbing foam was added into the bottom structure of the fuselage section. The calculated results indicate that the crashworthiness design can meet the corresponding specifications. The impact simulation was carried out using the professional nonlinear explicit transient dynamic finite element software. Compared with the test results, the calculated average acceleration does not exceed 13g, with the relative error being less than 11%. The maximum vertical impact load is less than 6 kN, and the persistent time of the average minus acceleration of crash is not more than 0.03 s. All these results are reasonable. The model can be used for the anti-crash design of the helicopter.