预应力组合下横梁临界预紧力影响因素研究  

Research on Influence Factors of Critical Pretension Force in Pre-stressed Assembled Lower Beam

作　　者：郭宝峰[1] 于琳琳[1] 金淼[1] 董晓传[1] 

机构地区：[1]燕山大学先进锻压成形技术与科学教育部重点实验室,秦皇岛066004

出　　处：《中国机械工程》2013年第19期2567-2572,共6页China Mechanical Engineering

基　　金：国家自然科学基金资助项目(50975248);国家科技重大专项(2013ZX04003-031)

摘　　要：由于受到加工、运输及安装等条件的限制,大型锻造液压机的下横梁通常由几块梁体利用预紧螺栓组装而成,因此如何计算合适的预紧力以保证组合梁的强度、刚度和整体性就成为组合下横梁设计的关键问题。以某企业大型锻造液压机组合下横梁为原型,建立了简化下横梁分析模型,对组合梁在中心工况和扩孔工况下拉杆临界预紧力的影响因素进行了系统研究,确定了临界预紧力的主要影响因素及各因素的影响规律。研究表明,工作载荷及跨高比是影响临界预紧力大小的关键因素,梁宽及拉杆位置对其影响相对较小,且临界预紧力系数随跨高比的增大呈线性增大的趋势,当跨高比一定时临界预紧力系数基本为定值。设计并制备了1∶7.2(实验模型与数值模拟模型的尺寸比)的组合下横梁模拟实验装置,利用该装置对模拟结果进行了验证。研究结果为大型锻造液压机下横梁拉杆预紧力的确定提供了理论依据。The lower beam of a large forging hydraulic press is usually assembled with a few pieces of beam body using some preload bolts due to the restrictions of the processing, transportations and installation conditions, so how to accurately calculate the pretension force become the crucial problems in strength, stiffness and integration property design of the assembled lower beam. A sim-plified analysis model of lower beam was assumed herein as a large forging hydraulic press prototype and the influence factors of critical pretension force in center and reaming working condition of the as-sembled lower beam were systematically studied, so as to find out the critical factors and the influence rules. The results show that the load and ratio of span and height are the critical factors, the beam width and bolt position have less influence on the critical pretension force, and the critical pretension force coefficient increases linearly with the increase of the ratio of span and height. On the other hand, the critical pretension force coefficientis also set when the ratio of span and height is as a fixed value. The experimental model of the assembled lower beam with the ratio 1 ： 7.2 was designed here-in, which verifies the simulation results based on the model and provides a theoretical basis for the de- termination of the assembled lower beam of the large forging hydraulic press.

关 键 词：组合下横梁 整体性 临界预紧力 影响因素 

分 类 号：TG315.4[金属学及工艺—金属压力加工]