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采用热力耦合有限元分析方法,由焊件材料的性能参数及焊接工艺参数建立了二维轴对称粘塑性热力耦合有限元模型,对35Cr2Ni4MoA材料环形工件的连续驱动摩擦焊过程进行了模拟,得到并分析了温度场、应力应变场以及轴向缩短量的变化规律.测量了实际焊件的轴向缩短量和飞边形状,并与计算结果进行了对比,结果表明,利用该模型得到的摩擦焊接头飞边形状和轴向缩短量的计算结果和试验结果吻合较好.建立的有限元模型有助于制定合理的焊接工艺参数. 相似文献
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建立了连续驱动摩擦焊接过程的三维和二维刚塑性热力耦合模型.在三维模型中考虑了摩擦面上环向摩擦力对摩擦焊接过程的影响.计算了GH4169合金棒材连续驱动摩擦焊接过程的温度场、应力场及变形场.将三维模型计算结果和二维轴对称模型的计算结果及试验结果进行综合对比分析.研究发现,三维模型和二维轴对称模型的温度场计算结果相差不大,并且都和试验结果吻合得很好;但与二维轴对称模型相比,三维模型由于考虑了环向摩擦力,其等效应力计算值更大,也更合理,其飞边形状和轴向缩短量的计算结果更接近试验结果.三维模型能更好地模拟摩擦焊接过程. 相似文献
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以AA6061铝合金为试验对象,基于ABAQUS/Explicit建立耗材摩擦焊三维完全热力耦合模型,分析温度场、等效塑性变形场、轴向缩短量和飞边形状,结果表明,焊接温度低于材料熔点为固相连接,焊接过程塑性金属大量挤出,形成蘑菇头形状的飞边,飞边温度处于480 ℃左右;在稳定焊接阶段,前进侧温度高于返回侧,在垂直于焊缝方向上,焊棒高温区大于焊板高温区,温度分布的不均使得涂层边缘处结合不良. 高温区域趋于稳定后,轴向缩短量和时间呈近线性关系,焊接结束时轴向缩短量为7.5 mm,高温区和塑性变形区都集中在摩擦界面附近的堆积区域. 相似文献
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在建立了45钢环形结构件连续驱动摩擦焊的二维热力耦合有限元模型的基础上,研究了焊接过程中的温度场与材料流动对飞边形成的影响规律.结果表明,在摩擦阶段,材料主要沿轴向流动,而径向流动基本上为0;在顶锻阶段,在大的轴向顶锻压力的挤压作用下,摩擦面边缘及其附近的材料主要沿径向向摩擦面外流动并形成飞边,且飞边的尺寸与弯曲程度随焊接时间的增加而增加.同时,增加旋转频率以及轴向顶锻压力会导致飞边尺寸与弯曲程度的增加;基于飞边形貌给出了45钢环节结构件连续驱动摩擦焊的合理焊接工艺参数. 相似文献
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基于弹塑性有限元理论,采用三维塑性体/塑性体摩擦副模型,考虑实际焊接过程中两侧工件散热条件的差异,建立了FGH96高温合金管惯性摩擦焊过程有限元模型,计算了焊接过程中瞬态温度场和轴向应力场的分布,研究了初始转速、顶锻力和转动惯量对接头温度场和飞边形貌的影响。模拟的飞边形貌与试验所得焊件误差仅为5%,验证模型的可靠性。模拟结果表明,惯性摩擦焊过程中,摩擦界面升温迅速,峰值温度可达1 335 ℃,塑性变形主要发生在距界面4 mm的区域内,该区域轴向温度梯度较大。摩擦界面附近压应力值从中心到边缘逐渐降低,界面边缘应力状态由压应力转变为拉应力,飞边根部由于挤压变形,存在压应力集中。提高初始转速和转动惯量均能增加焊接热输入,延长摩擦时间,提升峰值温度,增加飞边挤出量;加大顶锻力可提高机械能转化成热能的效率,缩短摩擦时间,增加轴向缩短量和飞边卷曲度。
创新点: 塑性体/塑性体有限元模型能够综合考虑接触面力的相互作用,采用更符合实际的三维双塑性体模型,对FGH96高温合金环形工件惯性摩擦焊过程进行了数值模拟。 相似文献
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在ABAQUS有限元软件二次开发环境下建立了GH4169高温合金管惯性摩擦焊接二维模型.采用了网格重划分技术模拟了不同焊接轴向压力对焊接接头温度场和轴向缩短量的影响.对温度场进行了综合分析,得到了不同轴向压力下接头温度场的变化规律.同时结合焊接接头轴向缩短量的变化,分析了轴向压力对接头飞边形貌的影响.结果表明,随着压力的增大,飞轮动能转化焊接热能效率明显提高,界面迅速到达高温动态平衡区间,有效形成均匀飞边;然而压力过大不利于接头温度均匀化,可能造成强烈的应力集中.压力参数为400 MPa可获得较佳质量接头. 相似文献
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Wenya Li Feifan Wang Shanxiang Shi Tiejun Ma Jinglong Li Achilleas Vairis 《Journal of Materials Engineering and Performance》2014,23(11):4010-4018
In this work, a 3D numerical model was developed to investigate the complicated thermo-mechanically coupled process of linear friction welding (LFW). The explicit-implicit alternate method was adopted for the first time to simulate LFW mild steel based on the ABAQUS software. To cope with the excessive element distortion, remeshing was conducted at certain calculation time with the help of the HYPERWORKS software. Results show that the interface temperature is quickly increased to near 900 °C within 1 s. With increasing the welding time, the interface temperature reaches a quasi-steady state of about 950 °C and the axial shortening rate keeps almost constant. A final unilateral axial shortening of 2.73 mm was obtained under the experiment condition, which corresponds well to the experiment. Moreover, the effects of processing parameters (oscillation frequency, oscillation amplitude, and friction pressure) on the joint temperature evolution and axial shortening were systematically examined and discussed. These three parameters could be integrated into one factor, i.e., heat input to the interface. 相似文献
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The Coupled FEM Analysis of the Transient Temperature Field During Inertia Friction Welding of GH4169 Alloy 总被引:1,自引:0,他引:1
L.W. Zhang J.B. Pei Q.Z. Zhang C.D. Liu W.H. Zhu S. Qu J.H. Wang 《金属学报(英文版)》2007,20(4):301-306
The inertia friction welding process is a non-linear process because of the interaction between the temperature field and the material properties as well as the friction force. A thermo-mechanical coupled finite element model is established to simulate the temperature field of this process. The transient temperature distribution during the inertia friction welding process of two similar workpieces of GH4169 alloy is calculated. The region of the circular cross-section of the workpiece is divided into a number of four-nodded isoparametric elements. In this model, the temperature dependent thermal properties, time dependent heat inputs, contact condition of welding interface, and deformation of the flash were considered. At the same time, the convection and radiation heat losses at the surface of the workpieces were also considered. A temperature data acquisition system was developed. The temperature at some position near the welding interface was measured using this system. The calculated temperature agrees well with the experimental data. The deformation of the flash and the factor affecting the temperature distribution at the welding interface are also discussed. 相似文献
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采用ABAQUS软件,以45钢为径向环,对钢管径向摩擦焊在假设变形速率前提下分析焊接界面温度场和径向环的加载力情况.计算采用了Johnson-cook幂硬化弹塑性模型,并考虑材料热物性与摩擦系数随温度变化.结果表明,在不考虑径向环与夹具之间传热的前提下,在焊接界面形成了以夹具体为中心的椭圆状温度梯度分布和以夹具体空隙为中心的条带状温度梯度分布,两处的最高温度达到1 260℃和1 050℃的前提下得到了加载力曲线.为了简化焊接工艺过程将加载力曲线人为拟合为定值三段加压过程,重新代入模型反复修正计算使界面温度场和径向环变形过程与焊接过程吻合良好. 相似文献
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《Acta Materialia》2008,56(12):2843-2855
For the first time a comparative thermal analysis of the friction welding process using various heat generation models is presented. The heat-generation rate in orbital friction welding of steel bars is analyzed using four different methods; constant Coulomb friction, sliding–sticking friction, the experimentally measured power data and an inverse heat conduction approach. A comparison between the calculated temperature profiles and the experimental data shows that the inverse heat conduction approach predicts the heat-generation rate accurately, whereas the constant friction coefficient approach leads to the most inaccurate temperature profile. Moreover, a three-dimensional thermomechanical finite element (FE) analysis based on the calculated heat input data and the experimental axial shortening rate demonstrates that the process can be analyzed in a one-dimensional domain due to the short frictional heating cycle and the uniform heat-generation rate across the interface. The FE analysis also indicates that the heat-generation rate due to the plastic deformation in the workpiece away from the interface is negligible compared to the heat-generation rate by friction. 相似文献