厚壁金属管挤压变形缓冲制动响应特性研究

金属管挤压变形是高效缓冲制动的重要形式,但目前对不同结构形式在动态冲击条件下的响应特性缺少系统的认识;以厚壁金属管为对象,对其挤压变形缓冲制动响应进行数值研究。参照试验状态和结果建立厚壁金属管缓冲制动装置的有限元分析计算模型,进行准静态仿真模拟分析并校核;在此基础上利用有限元法和显示动力学算法,对厚壁金属管缓冲制动响应特性以及影响缓冲力的主要因素进行研究和分析。结果表明:①厚壁金属管缓冲制动结构具有尺寸小、冲击载荷平稳、变形能力强的特点;②利用此计算模型能够清晰地表征厚壁金属管缓冲制动装置的动态响应;③影响缓冲力大小的主要结构因素是缓冲筒下部内孔直径、上部内孔直径以及外部直径,缓冲筒上下内径比D1应控制在0.7~0.8,D2应控制在1.8~2.0,当比值越小时,冲击杆会出现反冲现象,当比值越大时,冲击杆受到较大的冲击力,缓冲筒的惯性制动段的制动也有较大波动的影响。针对工程应用中不同的缓冲制动需求,可以通过设置合理的缓冲筒内外廓直径参数来获得有效的制动载荷。可为相关研究和工程应用提供参考。

Study on response characteristics of cushioning braking for extrusion deformation of thick-walled metal tube

The extrusion deformation of metal tube is an important form of high efficient cushioning braking.At present, the response characteristics of different structural forms under dynamic impact conditions is still lack of systematic understanding. Based on the thick-walled metal tube, the numerical study was carried out on the response of the compression deformation buffering braking. Firstly, with reference to the test state and results, the finite element analysis and calculation model of the thick-walled metal tube buffer braking device was established, and the quasi-static simulation analysis was carried out and checked, and then on this basis, the finite element method and display dynamics algorithm were used to study and analyze the cushioning braking response characteristics of thick-walled metal tube and the main factors affecting the buffer force. The results show that: ① the thick-walled metal tube buffer braking structure has the characteristics of small size, stable impact load and strong deformation capacity;② the dynamic response of the thick-walled metal tube buffer braking device can be clearly characterized by this calculation model;③the main structural factors affecting the buffer force are the lower inner hole diameter, the upper inner hole diameter and the external diameter of the buffer tube. The ratio of the inner diameter of the buffer tube to that of the upper part D1 should be controlled between 0.7 and 0.8, and the ratio D2 should be controlled between 1.8 and 2.0. When the ratio is smaller, the impact rod will recoil. When the ratio is larger, the impact rod will be subjected to greater impact force. The braking of the inertia braking section of the buffer cylinder also has a large fluctuation influence. According to the different buffer braking requirements in different engineering applications, the effective braking load can be obtained by setting reasonable parameters of the inner and outer diameter of the buffer tube. It can provide reference for related research and engineering application.