使用ANSYS软件，建立了使用激光透射焊接技术焊接透明聚氯乙烯(PVC)的三维有限元热分析模型，利用APDL编程实现高斯型热源的动态加载，得到了温度场的分布; 进一步分析了焊接速度、激光平均功率和光斑直径等工艺参数对焊接质量的影响，并计算出焊缝宽度。结果表明，随着焊接速度的增加，焊缝区域的最高温度逐渐降低，焊缝宽度逐渐减小;当激光平均功率增大时，焊缝区域的最高温度增高，焊缝宽度增大;而当光斑直径增大时，焊缝宽度增大，但焊缝处的最高温度有所下降。焊缝宽度计算值与实验测量值相比，二者比较吻合。

A three-dimensional (3-D) thermal model based on the finite element theory is implemented to simulate the temperature field on laser transmission welding of polyvinylchloride (PVC) by means of software ANSYS. With the ANSYS parametric design language APDL, a moving Gaussian distributed heat source is applied, and the distribution of the temperature field is gained. Effect of process parameters, including laser power, scanning welding and spot diameter, on the welding result is investigated, and the calculated melting width is obtained. The results show that with increasing of scanning speed, the maximum temperature and the melt width decrease; with increasing of laser average power, the maximum temperature and the melt width increase; with increasing of spot diameter, the maximum temperature decreases and the melt width increases. Very good agreement is achieved between the calculated value and the measured value.