气液环簧组合式缓冲器非对称拉压特性动力学建模及冲击仿真

为解决气液环簧组合式缓冲器呈现非对称拉压动态特性问题，构建了气液环簧组合式缓冲器动力学模型，基于MATLAB/Simulink软件编制了考虑不同吸能元件特性的车辆冲击动力学模型程序，研究了两辆单车冲击及两列动车组冲击的动态特性。研究结果表明:组合式缓冲器动力学模型既能有效地模拟拉伸状态下环簧缓冲器的线性加载特性，又能较好地模拟压缩状态下气液缓冲器随冲击速度变化的非线性加载动态特性，即组合式缓冲器动力学模型体现了明显的非对称拉压特性；低速与中高速冲击过程中，组合式缓冲器动力学模型及车辆冲击模型可依次完整有效地模拟缓冲器-压溃管-防爬器-车体结构变形产生的缓冲吸能动态过程及磁滞拉压特性曲线；列车冲击速度为5 km·h-1时，最大车钩力及组合式缓冲器最大行程均小于缓冲器阻抗力和行程限值，其压缩加载特性曲线仅呈现出气液缓冲器的加载特性；冲击速度为20 km·h-1时，最大车钩力为2 900 kN，最大行程为534 mm，防爬器已经触发，其压缩加载特性曲线呈现出了气液缓冲器-压溃管-防爬器组成的连续力学特性，此时车体结构未发生破坏；冲击速度达到25~30 km·h-1时，列车开始发生结构破坏，车钩力陡升；全自动车钩与半永久车钩参数选型能够满足冲击速度20 km·h-1以内的列车车体结构安全性。 

Dynamics modeling of asymmetrical tension and compression characteristics of gas-hydraulic and ring spring combined draft gear and impact simulation

A dynamics model of a gas-hydraulic and ring spring combined draft gear was established to simulate the asymmetric dynamic tension and compression characteristics of the gear.Based on the characteristics of different energy-absorbing elements, a vehicle impact dynamics model program was compiled using MATLAB/Simulink software, and the impact dynamic characteristics of two vehicles and two groups of EMUs were evaluated. Research results show that the linear loading characteristics of the ring spring draft gear under tension can be simulated precisely. Moreover, the varying nonlinear characteristics of the gas-hydraulic draft gear with impact speed under compression can be simulated satisfactorily using the combined draft gear dynamics model. The asymmetric tension and compression characteristics are shown in the combined draft gear dynamics model. Under low-speed and medium/high-speed impacts, the dynamic energy absorption process and hysteresis tension-compression characteristic curve can be entirely and effectively simulated using a combined draft gear dynamics and vehicle impact model. This is caused by the deformation of the draft gear, crushing tube, anticlimbing device, and vehicle body structure in sequence. When the impact speed is 5 km·h-1, the maximum coupler force and the maximum stroke of the combined draft gear are lower than the resistance force and stroke limit, and the loading characteristic curve of the gas-hydraulic draft gear only exhibits compression loading characteristics. When the impact speed is 20 km·h-1, the maximum coupler force is 2 900 kN, the maximum stroke is 534 mm, and the anticlimbing device is triggered. The continuous mechanical characteristics of the gas-hydraulic draft gear, crushing tube, and anticlimbing device are exhibited in the compression-loading characteristics curve, and the structure of the vehicle body is not damaged. When the impact speed reaches 25-30 km·h-1, the vehicle body structure is deformed, and the coupler force increases sharply. The structural safety of the vehicle body can be satisfied through the parameter selection of the fully automatic coupler and semi-permanent coupler within an impact speed of 20 km·h-1. 2 tabs, 12 figs, 33 refs.