【作者】 杨俊锋；

【导师】 肖宏；

【作者基本信息】 燕山大学 ， 机械设计及理论， 2023， 硕士

【摘要】 新能源汽车的发展使得人们越来越关注车身的轻量化问题,使用钢铝混合车身是减轻车身重量的一个有效方案。但由于性质的差异,钢-铝板材之间的连接问题一直等待解决。无铆连接技术作为一种新型冷变形连接方式,因其工艺简单、成本低,节能环保等优点逐渐被重视起来。本文以5052铝合金、低碳钢和中碳钢作为研究对象,设计了一套分体式的凹模,以便于凹模深度的更改。对整体模具进行了设计,并与万能试验机与压力传感器等组合,搭建了无铆连接实验平台,确立了整个实验的流程,并通过实验成功实现了铝合金和钢的有效连接。利用ABAQUS软件了建立无铆连接的有限元模型,对无铆连接成形过程进行了数值模拟,按照截面形貌特点将成形过程分为初期变形、互锁成形和过度挤压三个阶段,分析了各个阶段的应力和截面形貌特点,整理了接头成形过程中截面形貌参数的变化。对材料参数的影响进行了模拟,对比了不同叠放顺序和材料强度接头的应力状态与形貌参数。改变模具参数进行模拟,分析了冲头直径和凹模深度对截面形貌的影响。通过实验,测量了不同连接参数下接头的截面形貌参数,验证了模拟结果的可信度。测量了接头的剪切强度和剥离强度,分析力接头截面形貌参数和材料参数对接头机械性能的影响。对钢的表面进行氧化处理,对比了氧化对接头形貌和强度的影响。更多还原

【Abstract】 The development of new energy vehicles has drawn increasing attention to the issue of light-weighting the vehicle body.Using a steel-aluminum hybrid body is an effective solution to reduce the weight of the vehicle body.However,due to differences in their properties,the connection between steel and aluminum plates has been a long-standing issue that needs to be resolved.As a new type of cold forming connection,the mechanical clinch technology has gradually gained attention due to its simple process,low cost,energy conservation,environmental protection,and other advantages.This article takes 5052 aluminum alloy,low carbon steel,and medium carbon steel as research subjects,and designs a set of split die to facilitate the change of die depth.The overall mold is designed,and combined with universal testing machine and pressure sensors to build a mechanical clinch experimental platform,establish the entire experimental process,and successfully achieve the effective connection between aluminum alloy and steel through experiments.Establish a finite element model of mechanical clinch using ABAQUS software,and perform numerical simulation on the forming process of mechanical clinch.According to the cross-sectional topography characteristics,the forming process is divided into three stages: initial deformation,interlocking and over-extrusion.The stress and cross-sectional topography characteristics of each stage are analyzed,and the changes of cross-sectional topography parameters during the joint forming process are sorted out.Simulate the influence of material parameters,and compare the stress state and topography parameters of joints with different stacking sequences and material strength.Simulate the influence of mold parameters by changing the punch diameter and die depth,and analyze the effect of cross-sectional topography.Through experiments,the cross-sectional topography parameters of joints with different connection parameters were measured,and the credibility of the simulation results was verified.The shear strength and peel strength of joints were measured,and the influence of joint cross-sectional topography parameters and material parameters on joint mechanical properties was analyzed.The surface of steel was oxidized,and the effect of oxidation on joint topography and strength was compared.更多还原