JDA1b铝合金动态力学性能和预变形行为研究  

Dynamic mechanical performance and pre-deformation behavior of JDA1b alloy

作　　者：王雪强 彭立明[2] 李四平[1] WANG Xue-qiang;PENG Li-ming;LI Si-ping(School of Ocean and Civil Engineering,Shanghai Jiao Tong University,Shanghai 200240,China;School of Materials Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学船舶海洋与建筑工程学院,上海200240 [2]上海交通大学材料科学与工程学院,上海200240

出　　处：《船舶力学》2024年第11期1721-1730,共10页Journal of Ship Mechanics

基　　金：国家重点研发计划资助项目(2021YFB3701000);国家自然科学基金资助项目(51878407)。

摘　　要：铝合金因其低密度、高比强度和大比刚度等优点在船舶工业中得到了大量应用。但是相比于钢材,铝合金的强度偏低。为了提高铝合金材料的强度,以常应用于船舶压铸件和舾装件的JDA1b铝合金为研究对象,开展预变形拉伸和弯曲试验以及动态拉伸试验,研究预应变、预弯曲对JDA1b合金力学性能的影响,同时也研究应变率对合金流动力学行为的影响。结果表明:提高应变率能增加材料的流动应力和抗拉强度;随着预应变的增加,材料的屈服应力和抗拉强度会增大,但延伸率会降低;预弯量的增加有利于提高材料的弯曲屈服载荷、弯曲刚度和破坏位移。提出考虑极限强度和临界应变的新动态本构模型,该模型能够准确地预测JDA1b合金在不同应变率(1~800/s)时的流动应力,拟合优度值达到了0.999。本文的研究可为提高铝合金强度提供方法参考,新提出的本构模型有助于提高零件力学性能仿真计算的精度。Aluminum alloys have been widely used in the ship industry for their low density,high specific strength and specific stiffness.However,compared with steel,the strength of aluminum alloy is low.To im⁃prove its strength,JDA1b aluminum alloy,which is often used in die casting and outfitting parts of ships,was taken as the research object.Pre-strain tensile,pre-bend tests and dynamic tensile tests were carried out to investigate the effects of pre-strain and pre-bend on the mechanical performance of JDA1b alloy,and the ef⁃fects of strain rate on the flow behaviors of the alloy were also investigated.The results show that increasing the strain rate can increase the flow stress and tensile strength of the material;the yield stress and tensile strength of this material increase with the increase of pre-strain,and the elongation decreases,and that the increase of pre-bend is favorable to improve the bending yield load,bending stiffness and damage displace⁃ment of the material.A new dynamic constitutive model considering ultimate stress and critical strain was proposed,which allows the flow stress to be predicted more precisely at various strain rates over a wide range of 1~800/s,and the fitting goodness-of-fit value reached 0.999.This study provides methods to improve the strength of aluminum alloys,and the proposed constitutive model is conducive to the improvement of the ac⁃curacy of the simulation of mechanical performance of parts.

关 键 词：铝合金 预应变 预弯曲 动态 本构模型 力学性能 

分 类 号：U668.2[交通运输工程—船舶及航道工程]