直升机起落架抗坠毁性能的有限元仿真评估

 建立了直升机起落架抗坠毁有限元模型,模拟硬着陆和坠毁过程,以考察起落架在坠毁事故发生时的吸能能力。有限元建模使用真实的几何模型,用一个虚拟的框架代替机身把起落架连接起来,全机质量折算为减缩质量并分布到该框上。缓冲器用弹簧—阻尼器单元替代,其参数由性能曲线给出。使用非线性瞬态动力学的显式解法求解冲击问题。对两种情况进行了仿真:分别以6.0m/ s 和10.2m/ s 的垂直速度撞击地面。坠毁实验表明仿真结果与实验结果具有较好的一致性。

Crashworthiness Performance Evaluation to Helicopter Landing Gear by Finite Element Simulation

A finite element model of helicopter landing gears is developed to simulate hard landing and crash impact situations. The objective of the crash simulation is to evaluate the energy absorbing capability of the landing gear during a possible crash event. The landing gear system is modeled with a real geometrical configuration. The oleo-leg is represented by a spring-damper unit construction whose characteristics are acquired from performance calculation. A framework is used to connect the system, and the reduced mass of the helicopter is appended to it. A nonlinear, explicit transient dynamic code is employed to solve the impact problem. Two conditions are studied: the helicopter is impacted at 6.0m/s vertical velocity (hard landing) and at 10 2m/s one (crash). It shows that the prediction behaviors are well consistent with the crash test.