超声波塑料焊接区域材料熔接行为研究

【作者】 邓莹莹；

【导师】 梁延德；

【作者基本信息】 大连理工大学 ， 机械设计及理论， 2004， 硕士

【摘要】 超声波塑料焊接是一种经济、高效、环保的热塑性塑料连接新工艺，有极大的推广应用前景。由于超声波塑料焊接是涉及多学科的交叉学科，研究难度较大，目前超声波塑料焊接的焊接基础理论和工艺规范还比较欠缺，对超声波塑料焊接机理和熔接行为研究不足。为了得到满足要求的焊接强度，人们需要进行大量的试验，获得相应的焊接工艺参数，不仅费时费力，而且不能从根本上解决焊接质量提高的问题，制约了超声波塑料焊接技术的推广应用。 本文着眼于超声波塑料焊接区域材料的熔接行为研究，以解释焊接机理、提高焊接强度为目标，以工程硬质PVC材料为研究对象。由于超声波塑料焊接时间短，熔化区域狭小，焊接区域伴随材料的熔融和形变，温度场检测特别是多路巡检难度较大，所以本文采用试验和数值模拟相结合的方法，主要研究工作如下： 1)建立了超声波塑料焊接温度场自动检测系统，包括系统的软件和电路设计，实现了超声波温度场瞬变信号的一点采集。 2)采用ANSYS有限元的方法，建立了比较合理的超声波塑料焊接传热的数值模拟计算模型，模拟了超声波塑料焊接的温度场，温度采集试验结果和数值模拟结果基本符合。把试验结果和有限元计算结果结合起来，阐述了焊接区域的温度变化规律。 3)结合温度采集试验和数值模拟结果，深入分析了超声波塑料焊接的材料熔接过程，包括不同熔点材料的熔接特点和导能筋的熔接特点，对超声波塑料焊接的焊接机理提出了新的见解，为提高焊接强度提供了试验依据。 4)对导能筋熔接行为的研究，明确了导能筋焊口结构形式的积极作用。更多还原

【Abstract】 Ultrasonic plastic welding (UPW) is a cost-effective, efficient and clean fusion bonding technique of TPC (Thermal Plastic Composites), and of great value in application. At present basic theory and welding criterion of UPW are defective, research on welding mechanism and melt behavior of the welding region is not enough for the difficulty in study. To gain satisfactory mechanical strength, many experiments have to be done for optimum process parameters, in which both time and money are wasted in vain. Furthermore, many welding quality problems have not been solved yet. For these reasons UPW is restricted in popularizing in modern industry greatly.Research on ultrasonic plastic welding mechanism and the fusion bonding behavior of plastic in melt region is focused in this paper, the goal is to improve mechanical strength of the welding joints. Together with temperature field simulation by means of finite element method(realized by ANSYS), temperature field measurement is carried out to analyze the fusion bonding behavior rules of rigid PVC.The main topics of this paper are as follows:1. An automatic measurement system is setup to capture the transient temperature signal,including software and circuit design. Temperature data is captured successfully.2. The temperature field of the PVC specimens with energy director in ultrasonic welding issimulated by the finite element method (FEM). The simulation result is in agreement with the temperature measurement result, which proves that the simulation is reliable. With the result of FEM and temperature data acquisition, the temperature field change characteristic is analyzed.3. The fusion bonding behavior of welding region is discussed on the basis of experimentsand FEM simulation result, including plastic specimens with different melting point and with energy director. This contributes to the explanation of ultrasonic plastic welding mechanism and the improvement of fusion bonding strength of UPW.4. The research on fusion bonding behavior of energy director ensures its advantaged influence on ultrasonic plastic welding.更多还原