电磁制动器接触应力及瞬态温度场分析
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摘要
制动器的接触应力和温度场分布是影响制动器性能的重要因素。本文利用有限元分析方法,针对电磁制动器,根据其结构和工作原理,建立了三维有限元分析模型,对于电磁制动器工作过程中的电磁场、接触应力以及温度场问题进行了研究。
首先利用ANSYS软件,考虑电磁体底面与摩擦环之间磁接触问题以及空气气隙对于电磁吸力的影响,分析了磁感应强度在电磁体以及摩擦环之间的分布,得出了电磁吸力随气隙变化的关系曲线,并根据磁感应强度与电磁吸力之间的关系,分析了电磁吸力在电磁体内部的分布趋势,得出了磁感应强度和电磁吸力在电磁体内部均呈前后对称而左右不对称的结论。
在此基础上,分析了电磁体—摩擦环接触副以及制动衬片—制动鼓接触副在静止和转动状态下的接触应力分布。由于材料不同,电磁体上壳体底面、铁芯底面的接触应力要大于填充材料底面的接触应力。利用接触分析的结果,对电磁体工作工程中的姿态稳定性进行了分析,得出了电磁体在非对称电磁吸力以及摩擦力的作用下姿态稳定的结论。
在进行温度场分析时,考虑了摩擦生热率,空气对流散热以及热流在接触副之间的分配等因素,建立了制动器温度场分析模型。由于接触应力与温度场相互影响,采用间接耦合分析的方法,对于紧急制动工况以及下长坡工况下的电磁体温度场分布进行了分析,得到了电磁体在不同工况下的瞬态温度场变化。
最后,利用电磁制动器试验台和红外热成像仪,对于匀速工况下的电磁体模型进行了试验验证。热成像试验与有限元分析结果基本一致,证明了有限元模型、载荷以及边界条件设置的正确性。
本文的分析计算结果为进一步研究制动器的失效形式以及结构优化打下了良好的基础。
Contact pressure and temperature are key factors that greatly influence on the performance of brakes. A finite element model is built based on the special component of a new electric brake. Then the finite element method is used to analyze the magnetic field, contact pressure and temperature of electric brake.
Considering the magnetic contact between the electromagnet and the iron plate, the magnetic flux density in the electromagnet is studied with ANSYS. Then the electromagnetic force at different air gap is calculated and the relationship between electromagnetic force and air gap is drawn. And it is predicted that the electromagnetic force in the whole electromagnet is symmetrical in the front-rear direction and unsymmetrical in the left-right direction.
Contact pressure between electromagnet and iron plate, and contact pressure between brake lining and drum is studied. Because of the difference of materials for a electromagnet body, the contact pressure on the bottom of iron core and the up-shell is larger than that on the bottom of friction material. The stableness of electromagnet is studied and the conclusion is drawn. Due to the balanced torque, the electromagnet is stable in the brake process.
Considering the heat generation, the convection of air flow and the distribution of heat flux between the contact pair, a thermal analysis model for brake is established. Because the contact pressure of the contact pair and the temperature field of brake are in a coupled relationship, a coupled-field method is used to analyze the transient temperature field of brake.
The analysis results of down-hill process are verified with the infrared images taken with the infrared camera.
The results make a good foundation to the further study on the performance analysis and the structure optimization to the brake.
首先利用ANSYS软件,考虑电磁体底面与摩擦环之间磁接触问题以及空气气隙对于电磁吸力的影响,分析了磁感应强度在电磁体以及摩擦环之间的分布,得出了电磁吸力随气隙变化的关系曲线,并根据磁感应强度与电磁吸力之间的关系,分析了电磁吸力在电磁体内部的分布趋势,得出了磁感应强度和电磁吸力在电磁体内部均呈前后对称而左右不对称的结论。
在此基础上,分析了电磁体—摩擦环接触副以及制动衬片—制动鼓接触副在静止和转动状态下的接触应力分布。由于材料不同,电磁体上壳体底面、铁芯底面的接触应力要大于填充材料底面的接触应力。利用接触分析的结果,对电磁体工作工程中的姿态稳定性进行了分析,得出了电磁体在非对称电磁吸力以及摩擦力的作用下姿态稳定的结论。
在进行温度场分析时,考虑了摩擦生热率,空气对流散热以及热流在接触副之间的分配等因素,建立了制动器温度场分析模型。由于接触应力与温度场相互影响,采用间接耦合分析的方法,对于紧急制动工况以及下长坡工况下的电磁体温度场分布进行了分析,得到了电磁体在不同工况下的瞬态温度场变化。
最后,利用电磁制动器试验台和红外热成像仪,对于匀速工况下的电磁体模型进行了试验验证。热成像试验与有限元分析结果基本一致,证明了有限元模型、载荷以及边界条件设置的正确性。
本文的分析计算结果为进一步研究制动器的失效形式以及结构优化打下了良好的基础。
Contact pressure and temperature are key factors that greatly influence on the performance of brakes. A finite element model is built based on the special component of a new electric brake. Then the finite element method is used to analyze the magnetic field, contact pressure and temperature of electric brake.
Considering the magnetic contact between the electromagnet and the iron plate, the magnetic flux density in the electromagnet is studied with ANSYS. Then the electromagnetic force at different air gap is calculated and the relationship between electromagnetic force and air gap is drawn. And it is predicted that the electromagnetic force in the whole electromagnet is symmetrical in the front-rear direction and unsymmetrical in the left-right direction.
Contact pressure between electromagnet and iron plate, and contact pressure between brake lining and drum is studied. Because of the difference of materials for a electromagnet body, the contact pressure on the bottom of iron core and the up-shell is larger than that on the bottom of friction material. The stableness of electromagnet is studied and the conclusion is drawn. Due to the balanced torque, the electromagnet is stable in the brake process.
Considering the heat generation, the convection of air flow and the distribution of heat flux between the contact pair, a thermal analysis model for brake is established. Because the contact pressure of the contact pair and the temperature field of brake are in a coupled relationship, a coupled-field method is used to analyze the transient temperature field of brake.
The analysis results of down-hill process are verified with the infrared images taken with the infrared camera.
The results make a good foundation to the further study on the performance analysis and the structure optimization to the brake.
引文
[1]余志生.汽车理论(第3版).北京:机械工业出版社.2002
[2]陈家瑞.汽车构造(第3版).北京:人民交通出版社.1998
[3]袁伟.鼓式制动器温升模型及其应用研究.硕士学位论文.西安:长安大学.2003
[4]柳作民 等编.最新国际汽车制动法规汇编.中国汽车工程学会制动专业委员会.1997
[5]Yun-Bo Yi,J.R.Barber etc.Eigenvalue solution of thermoelastic instability problem using Fourier reduction.Proc.R.Soc.Lond.A.2000:2799-2821
[6]Kwangjin Lee,J.R.Barber.Frictionally excited thermoelastic instability in automotive disk brakes.ASME journal of Tribology.1993:607-614
[7]Kwangjin Lee.Frictionally excited thermoelastic instability in automotive drum brakes.ASME journal of Tribology.2000:849-855
[8]Yun-Bo Yi.Effect of geometry on thermoelastic instability in disk brakes and clutches.ASME Journal of Tribology.1999:661-666
[9]A.E.Anderson,R.A.Knapp.Hot spotting in automotive friction systems.Wear.1990:319-337
[10]马保吉,朱均.摩擦制动器接触表面温度计算模型.西安工业学院学报.1999.1
[11]唐旭晟.盘式制动器热—结构非线性分析与计算.硕士学位论文.福州大学.2003
[12]林谢昭.盘式制动器非轴对称瞬态温度场的数值模拟.硕士学位论文.福州大学.2000
[13]毛智东等.鼓式制动器接触分析.华中科技大学学报.2002(7)
[14]王营.盘式制动器摩擦片的温度场研究.武汉工业大学学报.2001(5)
[15]王营.温度分布对制动摩擦性能的影响.武汉工业大学学报.2000(10)
[16]吕振华等.蹄-鼓式制动器热弹性耦合有限元分析.机械强度.2003
[17]周凡华等.盘式制动器15次循环制动温度计算.汽车工程.2001(6)
[18]Thomas Valvano,Kwangjin Lee etc.An Analytical Method to Predict Thermal Distortion of a Brake Rotor.SAE.2000
[19]P.loannidis,P.C.Brooks etc.Drum brake contact analysis and its influence on squeal noise prediction.SAE.2003
[20]Ahmed ILM.Behavioural study of friction material by using finite element methods.SAE.2000
[21]Shih-Wei Kung.Brake squeal analysis incorporating contact conditions and other nonlinear effects.SAE.2003
[22]D.Suryatama.Contact mechanics simulation for hot spots investigation.SAE.2001
[23]Rajesh Somnay.Improved drum brake performance prediction considering coupled thermal and mechanical effects.SAE.2001
[24]Shan Shih.Improved drum brake shoe factor prediction with the consideration of system compliance.SAE.2001
[25]A.R.Abu Bakar.Interface pressure distributions through structural modifications.SAE.2003
[26]王勖晟.有限单元法.北京:清华大学出版社.2003
[27]李润方 龚剑霞编著.接触问题数值方法及其在机械设计中的应用.重庆:重庆大学出版社.1991
[28]张汝清 詹先义 编著.非线性有限元分析.重庆:重庆大学出版社.1990
[29]杨世铭 陶文铨 编著.传热学(第三版).高等教育出版社.1998.
[30]王勖成 邵敏 编著.有限单元法基本原理和数值方法.清华大学出版社.1997
[31]博弈工作室编著.APDL参数化有限元分析技术及其应用实例.北京:中国水利水电出版社.2004
[32]ANSYS INC.Structural Analysis Guide Release 7.0.SAS,IP Inc.2002
[33]ANSYS INC.Electromagnetic Field Analysis Guide Release 7.0.SAS, IP Inc.2002
[34]唐兴伦等.ANSYS工程应用教程-热与电磁学篇.北京:中国铁道出版社.2003
[35]小飒工作室编 最新经典ANSYS及workbench教程,北京:电子工业出版社.2004
[36]格利布著 数值法解摩擦学技术问题.北京:机械工业出版社.1989
[37]鲁道夫编,张慰林 陈名智译.汽车制动系统的分析与设计.北京:机械工业出版社.1985
[38]Rudolf Limpert.Brake design and safety.Society of Automotive Engineers Inc.1998
[39]张智铁.盘式制动器热特性分析.工程机械.1980(5)
[40]成大先主编.机械设计手册(第4版).北京:化学工业出版社.2002
[2]陈家瑞.汽车构造(第3版).北京:人民交通出版社.1998
[3]袁伟.鼓式制动器温升模型及其应用研究.硕士学位论文.西安:长安大学.2003
[4]柳作民 等编.最新国际汽车制动法规汇编.中国汽车工程学会制动专业委员会.1997
[5]Yun-Bo Yi,J.R.Barber etc.Eigenvalue solution of thermoelastic instability problem using Fourier reduction.Proc.R.Soc.Lond.A.2000:2799-2821
[6]Kwangjin Lee,J.R.Barber.Frictionally excited thermoelastic instability in automotive disk brakes.ASME journal of Tribology.1993:607-614
[7]Kwangjin Lee.Frictionally excited thermoelastic instability in automotive drum brakes.ASME journal of Tribology.2000:849-855
[8]Yun-Bo Yi.Effect of geometry on thermoelastic instability in disk brakes and clutches.ASME Journal of Tribology.1999:661-666
[9]A.E.Anderson,R.A.Knapp.Hot spotting in automotive friction systems.Wear.1990:319-337
[10]马保吉,朱均.摩擦制动器接触表面温度计算模型.西安工业学院学报.1999.1
[11]唐旭晟.盘式制动器热—结构非线性分析与计算.硕士学位论文.福州大学.2003
[12]林谢昭.盘式制动器非轴对称瞬态温度场的数值模拟.硕士学位论文.福州大学.2000
[13]毛智东等.鼓式制动器接触分析.华中科技大学学报.2002(7)
[14]王营.盘式制动器摩擦片的温度场研究.武汉工业大学学报.2001(5)
[15]王营.温度分布对制动摩擦性能的影响.武汉工业大学学报.2000(10)
[16]吕振华等.蹄-鼓式制动器热弹性耦合有限元分析.机械强度.2003
[17]周凡华等.盘式制动器15次循环制动温度计算.汽车工程.2001(6)
[18]Thomas Valvano,Kwangjin Lee etc.An Analytical Method to Predict Thermal Distortion of a Brake Rotor.SAE.2000
[19]P.loannidis,P.C.Brooks etc.Drum brake contact analysis and its influence on squeal noise prediction.SAE.2003
[20]Ahmed ILM.Behavioural study of friction material by using finite element methods.SAE.2000
[21]Shih-Wei Kung.Brake squeal analysis incorporating contact conditions and other nonlinear effects.SAE.2003
[22]D.Suryatama.Contact mechanics simulation for hot spots investigation.SAE.2001
[23]Rajesh Somnay.Improved drum brake performance prediction considering coupled thermal and mechanical effects.SAE.2001
[24]Shan Shih.Improved drum brake shoe factor prediction with the consideration of system compliance.SAE.2001
[25]A.R.Abu Bakar.Interface pressure distributions through structural modifications.SAE.2003
[26]王勖晟.有限单元法.北京:清华大学出版社.2003
[27]李润方 龚剑霞编著.接触问题数值方法及其在机械设计中的应用.重庆:重庆大学出版社.1991
[28]张汝清 詹先义 编著.非线性有限元分析.重庆:重庆大学出版社.1990
[29]杨世铭 陶文铨 编著.传热学(第三版).高等教育出版社.1998.
[30]王勖成 邵敏 编著.有限单元法基本原理和数值方法.清华大学出版社.1997
[31]博弈工作室编著.APDL参数化有限元分析技术及其应用实例.北京:中国水利水电出版社.2004
[32]ANSYS INC.Structural Analysis Guide Release 7.0.SAS,IP Inc.2002
[33]ANSYS INC.Electromagnetic Field Analysis Guide Release 7.0.SAS, IP Inc.2002
[34]唐兴伦等.ANSYS工程应用教程-热与电磁学篇.北京:中国铁道出版社.2003
[35]小飒工作室编 最新经典ANSYS及workbench教程,北京:电子工业出版社.2004
[36]格利布著 数值法解摩擦学技术问题.北京:机械工业出版社.1989
[37]鲁道夫编,张慰林 陈名智译.汽车制动系统的分析与设计.北京:机械工业出版社.1985
[38]Rudolf Limpert.Brake design and safety.Society of Automotive Engineers Inc.1998
[39]张智铁.盘式制动器热特性分析.工程机械.1980(5)
[40]成大先主编.机械设计手册(第4版).北京:化学工业出版社.2002