针对惯性约束聚变（ICF）驱动装置中口径为400 mm×400 mm薄型频率转换KDP晶体在45°放置状态下产生的附加面形问题，采用有限元分析软件ANSYS，建立了以实测数据为基础的大口径薄型KDP晶体的应变模型和有加工误差的夹具模型，仿真分析了KDP晶体的加工误差和夹具的加工误差对KDP晶体附加面形的影响， 给出了KDP晶体附加面形变化的P-V值和RMS值。在此基础上，通过对KDP晶体的加工误差及夹具支撑表面不同类型和不同大小加工误差的分析和比较，得出：KDP晶体边缘的加工误差和夹具支撑表面的凹型加工误差是引起较大附加面形的原因之一，KDP晶体的加工误差也会导致其面形变化不均匀，而夹具支撑表面的凸型、波浪形加工误差和压条表面的随机加工误差对KDP晶体附加面形的影响相对较小，且支撑表面的随机加工误差引起的附加面形变化介于其他两者之间。

Considering the additional surface variation of large-aperture thin KDP crystal placed with the departure angle of 45° from the horizontal plane in inertial confinement fusion (ICF) systems, which caused by the fabrication errors of KDP crystal and its mounting system, a finite element analysis model has been built up for the KDP crystal based on the experimental measurement data of surface profile and its mounting system with fabrication errors of different types and sizes. The influence of the fabrication errors of KDP crystal and its mounting system on the additional surface variation of KDP crystal has been simulated and the P-V and RMS values of the crystal surface profiles have been given. It is shown that the fabrication error of the edges of KDP crystal and the concave fabrication error of support surface of mounting system are important reasons for relatively large additional surface variation, and the fabrication error of KDP crystal leads to nonuniform deformation. Whereas the convex and wavy fabrication errors of support surface and the random fabrication error of strip surface of the mounting system lead to relatively small additional surface variation. The additional surface variation caused by the random fabrication error of support surface is in between.