Heat Generation During Mechanical Joining Processes – by the Example of Flat-Clinching☆
Heat Generation During Mechanical Joining Processes – by the Example of Flat-Clinching☆
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DOI：
10.1016/j.proeng.2017.04.093
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
S. Härtel;M. Graf;T. Gerstmann;B. Awiszus
中科院分区：
文献类型：
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作者：
S. Härtel;M. Graf;T. Gerstmann;B. Awiszus
在机械连接过程中，连接区出现高等效塑性应变(例如，平接：φeqv>3.0)。这导致了成形区内的高变形能。在冷体积成形中，由于晶界的内耗，大约80%的塑性能被转化为热。与其他成形工艺相比，机械连接工艺具有加工时间短、应变速率高的特点。因此，转换后的热不能通过热辐射或热传导从成型区散失。出于这个原因，预计联合区域将出现显著的供暖。在这项工作的范围内，应对出现的热进行实验和数值分析。在接头区域有极高的接触压力，这将导致任何热电偶的破坏。因此，不可能在实验上确定成形区域内的温度。为此，开发了一套基准装置，用于确定平压过程中的温升。该测量作为验证数值温度计算的基础。在数值研究中，分析了部件加热对成形结果和成形力的影响，并与不考虑加热的模拟结果进行了比较。
During mechanical joining processes, high equivalent plastic strains occur in the joint area (e.g., flat-clinching:φeqv>3.0). This causes a high deformation energy within the forming zone. In cold bulk forming, approximately 80% of the plastic energy is converted into heat due to internal friction at the grain boundaries. Compared to other forming processes, mechanical joining processes are characterized by short process times and high strain rates. Therefore, the converted heat cannot dissipate from the forming zone by heat radiation or heat conduction. For this reason, a significant heating of the joint area is expected. Within the scope of this work, the emerging heat shall be analyzed experimentally as well as numerically. There is an extremely high contact pressure in the joint area, which would result in a destruction of any thermocouple. Hence, it is not possible to determine experimentally the temperature within the forming zone. For this reason, a reference setup was developed for determining the increase of temperature during flat-clinching. This measurement serves as a basis for the verification of the numerical temperature calculation. During the numerical investigations, the influence of the component heating on the forming result and forming forces was analyzed and compared to simulations without consideration of the heating.