金属板材循环拉压加载中力学行为的演化
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摘要
在曲梁往复弯曲过程中,曲梁上任意质点均发生循环拉压加载变形,但目前对往复弯曲过程中的力学行为仍不明确。为深入认识往复弯曲变形过程中宏观力学行为的演化规律,采用对称恒应变幅控制方式进行低周次不同应变幅值条件下的小应变循环拉压加载试验,研究了304不锈钢和ST12冷轧板两种材料循环拉压加载条件下的宏观力学表现,探究了弹性模量、屈服应力和塑性模量随循环周次的变化规律和预应变对稳定滞后回线的影响。试验研究表明:304不锈钢和ST12两种材料均具有循环软化特性;经循环拉压加载后,两种材料的弹性模量、屈服应力和塑性模量发生明显改变,而且拉压不具有一致性;循环拉压加载可湮灭预应变造成的材料力学性能初始差异,使材料力学性能变得均匀一致,也间接证明了往复弯曲可将同层纤维力学性能均匀化,为新本构关系的构建奠定了基础。
In the process of reciprocating bending, any particle of the curved beam is subjected to cyclic tension-compression deformation. However, the mechanical behaviour of reciprocating bending is still not clear. In order to understand the evolution law of macroscopic mechanical behaviour in the process of reciprocating bending, the small strain cyclic tension-compression test of low cycle is carried out by the symmetric constant strain amplitude control model. The macroscopic performance on the 304 stainless steel and ST12 cold rolled plate under cyclic tension-compression loading is studied; the variation laws of elastic modulus, yield stress and plastic modulus with cycle times are investigated; the effect of prestrain is studied on the stable hysteresis loop. The experimental results show that 304 stainless steel and ST12 cold rolled plate are characterized by cyclic softening; after cyclic tension-compression loading, the elastic modulus, yield stress and plastic modulus of the two kinds of materials change obviously, and the tension and compression do not have consistency; cyclic tension-compression loading can annihilate the initial difference of mechanical properties caused by prestrain, and make the mechanical properties of materials become uniform. It is also indirectly proved that reciprocating bending can make the mechanical properties of the same layer of fibers be homogenized, which lays the foundation for the construction of the new constitutive relationship.
In the process of reciprocating bending, any particle of the curved beam is subjected to cyclic tension-compression deformation. However, the mechanical behaviour of reciprocating bending is still not clear. In order to understand the evolution law of macroscopic mechanical behaviour in the process of reciprocating bending, the small strain cyclic tension-compression test of low cycle is carried out by the symmetric constant strain amplitude control model. The macroscopic performance on the 304 stainless steel and ST12 cold rolled plate under cyclic tension-compression loading is studied; the variation laws of elastic modulus, yield stress and plastic modulus with cycle times are investigated; the effect of prestrain is studied on the stable hysteresis loop. The experimental results show that 304 stainless steel and ST12 cold rolled plate are characterized by cyclic softening; after cyclic tension-compression loading, the elastic modulus, yield stress and plastic modulus of the two kinds of materials change obviously, and the tension and compression do not have consistency; cyclic tension-compression loading can annihilate the initial difference of mechanical properties caused by prestrain, and make the mechanical properties of materials become uniform. It is also indirectly proved that reciprocating bending can make the mechanical properties of the same layer of fibers be homogenized, which lays the foundation for the construction of the new constitutive relationship.
引文
[1]于高潮,赵军,邢娇娇,等.对称式三辊矫圆工艺研究[J].机械工程学报,2017,53(14):136-143.YU Gaochao,ZHAO Jun,XING Jiaojiao,et al.Research on the symmetrical three-roller setting round process[J],Journal of Mechanical Engineering,2017,53(14):136-143.
[2]ZHAO Jun,YU Gaochao,MA Rui.A mechanical model of symmetrical three-roller setting round process:The static bending stage[J].Journal of Materials Processing Technology,2016,231:501-512.
[3]YU Gaochao,ZHAO Jun,ZHAI Ruixue,et al.Theoretical analysis and experimental investigations on the symmetrical three-roller setting round process[J].International Journal of Advanced Manufacturing Technology,2018,94:45-56.
[4]YU Gaochao,ZHAI Ruixue,ZHAO Jun,et al.Theoretical analysis and numerical simulation on the process mechanism of two-roller straightening[J].International Journal of Advanced Manufacturing Technology,2018,9(9-12):4011-4021.
[5]于高潮,赵军,马瑞,等.往复弯曲统一曲率定理及其试验验证[J].机械工程学报,2016,18:57-63.YU Gaochao,ZHAO Jun,MA Rui,et al.The uniform curvature theorem by reciprocating bending and its experimental verification[J].Journal of Mechanical Engineering,2016,18:57-63.
[6]赵永翔,王金诺,高庆.概率循环应力─应变曲线及其估计方法[J].机械工程学报,2000,8:102-106.ZHAO Yongxiang,WANG Jinnuo,GAO Qing.Probabilistic cyclic stress-strain curve and its estimation method[J].Journal of Mechanical Engineering,2000,8:102-106.
[7]金淼,李群,蔡星周,等.板材通过拉深筋时的循环塑性变形机理分析[J].机械工程学报,2013,49(12):38-42.JIN Miao,LI Qun,CAI Xingzhou,et al.Research on cyclic plastic deformation mechanism of sheet flowing through drawbead[J].Journal of Mechanical Engineering,2013,49(12):38-42.
[8]张庆玲,金淼,张洪生,等.小变形循环载荷下Q235材料特性的试验研究[J].机械工程学报,2017,53(20):69-76.ZHANG Qingling,JIN Miao,ZHANG Hongsheng,et al.Experiment research on material characteristics of q235under small deformation cyclic loading[J].Journal of Mechanical Engineering,2017,53(20):69-76.
[9]张功庭,盛光敏,黄利.金属包申格效应的表征、影响因素与机理研究进展[J].材料导报,2008,22(s3):135-138.ZHANG Gongting,SHENG Guangmin,HUANG Li.Research progress in characterization,influencing factors and mechanisms of bauschinger effect in metals material[J].Materials Review,2008,22(s3):135-138.
[10]ZANG Shunlai,LEE MG,LI Sun,et al.Measurement of the Bauschinger behavior of sheet metals by three-point bending springback test with pre-strained strips[J].International Journal of Plasticity,2014,59(10):84-107.
[11]MUTRUX A,BERISHA B,HORA P.Prediction of cyclic softening in a medium carbon steel during cross roll straightening[J].Journal of Materials Processing Technology,2011,211(8):1448-1456.
[12]ZHAO Kunmin.Cyclic stress-strain curve and springback simulation[D].Ohio:The Ohio State University,1999.
[13]YOSHIDA F.A constitutive model of cyclic plasticity[J].International Journal of Plasticity,2000,16(3-4):359-380.
[14]YOSHIDA F,UEMORI T,FUJIWARA K.Elastic-plastic behavior of steel sheets under in-plane cyclic tension-compression at large strain[J].International Journal of Plasticity,2002,18:633-659.
[15]KHUTIA N,DEY P,HASSAN T.An improved nonproportional cyclic plasticity model for multiaxial low-cycle fatigue and ratcheting responses of 304stainless steel[J].Mechanics of Materials,2015,91:12-25.
[16]HU Fangxin,SHI Gang,SHI Yongjiu.Constitutive model for full-range elasto-plastic behavior of structural steels with yield plateau:Calibration and validation[J].Engineering Structures,2016,118:210-227.
[17]ZHAO Jun,YIN Jing,MA Lixia,et al.Springback equation of small curvature plane bending[J].Science China:Technological Sciences,2011,54(9):2386-2396.
[18]American Society of Testing Materials.Standard practice for strain-controlled fatigue testing[S].West Conshohocken,United States,1998.
[19]ZHAO Jun,ZHAN Peipei,MA Rui,et al.Quantitative prediction of reduction in large pipe setting round process[J].Chinese Journal of Mechanical Engineering,2013,26(4):722-729.
[20]ZHAO Jun,SONG Xiaokang.Control strategy of multi-point bending one-off straightening process for LSAW pipes[J].International Journal of Advanced Manufacturing Technology,2014,72:1615-1624.
[2]ZHAO Jun,YU Gaochao,MA Rui.A mechanical model of symmetrical three-roller setting round process:The static bending stage[J].Journal of Materials Processing Technology,2016,231:501-512.
[3]YU Gaochao,ZHAO Jun,ZHAI Ruixue,et al.Theoretical analysis and experimental investigations on the symmetrical three-roller setting round process[J].International Journal of Advanced Manufacturing Technology,2018,94:45-56.
[4]YU Gaochao,ZHAI Ruixue,ZHAO Jun,et al.Theoretical analysis and numerical simulation on the process mechanism of two-roller straightening[J].International Journal of Advanced Manufacturing Technology,2018,9(9-12):4011-4021.
[5]于高潮,赵军,马瑞,等.往复弯曲统一曲率定理及其试验验证[J].机械工程学报,2016,18:57-63.YU Gaochao,ZHAO Jun,MA Rui,et al.The uniform curvature theorem by reciprocating bending and its experimental verification[J].Journal of Mechanical Engineering,2016,18:57-63.
[6]赵永翔,王金诺,高庆.概率循环应力─应变曲线及其估计方法[J].机械工程学报,2000,8:102-106.ZHAO Yongxiang,WANG Jinnuo,GAO Qing.Probabilistic cyclic stress-strain curve and its estimation method[J].Journal of Mechanical Engineering,2000,8:102-106.
[7]金淼,李群,蔡星周,等.板材通过拉深筋时的循环塑性变形机理分析[J].机械工程学报,2013,49(12):38-42.JIN Miao,LI Qun,CAI Xingzhou,et al.Research on cyclic plastic deformation mechanism of sheet flowing through drawbead[J].Journal of Mechanical Engineering,2013,49(12):38-42.
[8]张庆玲,金淼,张洪生,等.小变形循环载荷下Q235材料特性的试验研究[J].机械工程学报,2017,53(20):69-76.ZHANG Qingling,JIN Miao,ZHANG Hongsheng,et al.Experiment research on material characteristics of q235under small deformation cyclic loading[J].Journal of Mechanical Engineering,2017,53(20):69-76.
[9]张功庭,盛光敏,黄利.金属包申格效应的表征、影响因素与机理研究进展[J].材料导报,2008,22(s3):135-138.ZHANG Gongting,SHENG Guangmin,HUANG Li.Research progress in characterization,influencing factors and mechanisms of bauschinger effect in metals material[J].Materials Review,2008,22(s3):135-138.
[10]ZANG Shunlai,LEE MG,LI Sun,et al.Measurement of the Bauschinger behavior of sheet metals by three-point bending springback test with pre-strained strips[J].International Journal of Plasticity,2014,59(10):84-107.
[11]MUTRUX A,BERISHA B,HORA P.Prediction of cyclic softening in a medium carbon steel during cross roll straightening[J].Journal of Materials Processing Technology,2011,211(8):1448-1456.
[12]ZHAO Kunmin.Cyclic stress-strain curve and springback simulation[D].Ohio:The Ohio State University,1999.
[13]YOSHIDA F.A constitutive model of cyclic plasticity[J].International Journal of Plasticity,2000,16(3-4):359-380.
[14]YOSHIDA F,UEMORI T,FUJIWARA K.Elastic-plastic behavior of steel sheets under in-plane cyclic tension-compression at large strain[J].International Journal of Plasticity,2002,18:633-659.
[15]KHUTIA N,DEY P,HASSAN T.An improved nonproportional cyclic plasticity model for multiaxial low-cycle fatigue and ratcheting responses of 304stainless steel[J].Mechanics of Materials,2015,91:12-25.
[16]HU Fangxin,SHI Gang,SHI Yongjiu.Constitutive model for full-range elasto-plastic behavior of structural steels with yield plateau:Calibration and validation[J].Engineering Structures,2016,118:210-227.
[17]ZHAO Jun,YIN Jing,MA Lixia,et al.Springback equation of small curvature plane bending[J].Science China:Technological Sciences,2011,54(9):2386-2396.
[18]American Society of Testing Materials.Standard practice for strain-controlled fatigue testing[S].West Conshohocken,United States,1998.
[19]ZHAO Jun,ZHAN Peipei,MA Rui,et al.Quantitative prediction of reduction in large pipe setting round process[J].Chinese Journal of Mechanical Engineering,2013,26(4):722-729.
[20]ZHAO Jun,SONG Xiaokang.Control strategy of multi-point bending one-off straightening process for LSAW pipes[J].International Journal of Advanced Manufacturing Technology,2014,72:1615-1624.