共查询到20条相似文献,搜索用时 219 毫秒
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针对奥氏体不锈钢0Crl8Ni9的TIG焊接过程,建立了相应的数学模型和物理模型,并基于ANSYS平台进行有限元计算,分析了双椭球热源模型各参数对熔合区、热影响区分布和边界走向以及焊接温度场的影响规律。结果表明,在其他条件一定的情况下,热源宽度参数b主要影响熔合区和热影响区的宽度尺寸,热源深度参数c主要影响熔合区和热影响区的深度尺寸。研究还发现,熔合区的温度场分布和温度峰值对热源模型参数的变化较为敏感。 相似文献
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本文介绍了一种插入深度可调的温度受感器的设计过程,从安全系数分析和误差分析2方面介绍了温度受感器设计的主要流程。深度可调的设计,能方便地获得更多的测试参数,为发动机研制提供帮助,一定程度上节约了加工成本和时间成本。 相似文献
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40Cr钢磨削强化的试验与数值仿真 总被引:12,自引:0,他引:12
利用磨削过程中产生大量的磨削热使40Cr钢表层的温度升高,超过奥氏体化的温度,然后快速冷却,使40Cr钢表层发生马氏体相变,达到强化40Cr钢表层的目的。在磨床上对40Cr钢进行磨削试验,观测并分析工件横断面相变层的组织变化、厚度值和硬度变化,以及加工后工件表面的粗糙度。借助有限元分析方法,对工件的温度场进行仿真,得出工件各处的温度变化历程,由马氏体相变条件来获得表层马氏体相变层的厚度值。试验结果表明,40Cr钢的表层发生了马氏体相变,表层的硬度值得到极大提高,表面粗糙度也满足常规磨削的要求。由有限元仿真得出的相变层厚度值和试验结果相吻合。因此利用磨削强化技术替代40Cr钢高频淬火强化工艺是可行的,并且这项技术可以对其他合金钢进行强化。借助有限元方法对工件表层的温度场进行仿真,可以预测相变是否发生和相变层的厚度,优化磨削参数,减少试验研究的次数和成本。 相似文献
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根据金属塑性变形理论,提出了在低速正交金属切削中工件表面层加工硬化深度的预报准则。讨论了切削变形区内的弹塑性应力场,建立了剪切平面边界载荷的分布方程,并通过有限元法模拟已加工表面的形成过程,计算了工件表面层的应力和硬化深度。数值分析与试验研究相一致。 相似文献
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《Measurement》2016
The prediction of temperature distribution is a critical process in the study of welding thermal field. Therefore, the accuracy in temperature measurement is quite important to provide meaningful results and to establish the coupling among thermal field results and other studies in welding as mechanical and microstructural analyses. This work deals with statistical analysis and design of experiments (DoE) in order to establish an optimal experimental design for thermal history measurements in welding processes with thermocouples independent of base material. Calculations from theoretical correlations and computational modeling of heat flow were used to accomplish the present study. The Gas Tungsten Arc Welding process (GTAW) was used in the experiments along with plates of a structural steel (ASTM A 36) and a martensitic stainless steel (AISI CrMo 12-1). Four different parameters were studied related with the disposition, separation, depth, thermocouple arrangement and application of thermal paste. An optimal design was able to measure the maximum temperatures in adjacent zones to the weld bead, which are important for the study of welding thermal behavior. 相似文献
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高速正交切削SiCp/Al复合材料切削温度仿真研究 总被引:1,自引:0,他引:1
使用ABAQUS有限元软件对高体分SiCp/Al复合材料的颗粒和基体进行分别定义,仿真研究了高速切削复合材料时的温度场,分析了切削过程中切削用量和刀具角度对工件切削温度的影响。结果表明:在切削过程中,与刀具接触位置的颗粒温度较高且应力值较高;SiC颗粒的温度较Al基体的温度低;第一变形区发现一条沿着剪切角方向非常明显的温升带。在稳定切削阶段,与刀尖接触位置的工件温度较高,且应力集中现象总是发生在SiC颗粒上。随着切削深度和切削深度的增加,切削过程中工件的最高温度均随之增加;随着刀具前角和后角的增大,切削过程中工件的最高温度均随之降低。 相似文献
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针对电子耦合器件(CCD)辐射测温中因温度过高导致的辐射图像“发白”问题,提出了摄像机快门时间控制模型,该模型能有效地防止CCD光敏面输出过饱和电流。在此基础上,引入计算机断层图像检测理论,对燃烧火焰不同聚焦面的CCD成像过程进行研究,建立了用单一摄像机实现火焰深度方向聚焦面辐射图像与温度场分布关联模型,实现了火焰深度二维温度场的在线测量。实验室煤气燃烧实验表明:黑体炉标定后的关联模型实现了燃烧火焰内部温度场的在线测量与诊断,快门控制模型能有效解决辐射图像“发白”问题,扩大了CCD辐射测量的温度范围。 相似文献
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Bar check is the routine procedure in depth sounding to eliminate temperature influencing effect during the oceanographic surveying. This paper adopted the bar check concept prior to stream stage measuring on-site to improve the measuring accuracy and efficiency with popular ultrasonic sensor gauges. This study also propose both experimental dimensionless curves/corresponding equations and the relative profile of calibrating coefficients and ambient temperature of the specific ultrasonic sensor to accelerate the field calibrating process and for the bar check calibrating procedure being unavailable before the formal stage measuring. Then, field stage measuring data by a float-type gauge with which relative reliable measuring result being identified were compared with the data by an ultrasonic sensor gauge measuring simultaneously at the same location and obtained quite similar results. This advanced and improved stage measuring technique of ultrasonic sensor gauges without sonic conduit has been proved its practical validity in field stage accurate measuring throughout the on-site bar check procedure and introduced the process with dimensionless curves/formulas and relative correlation profile between calibrating coefficients and ambient temperature as well. 相似文献