The fracture strength of photovoltaic silicon wafers is affected by factors such as slicing process parameters and saw wire parameters. This paper numerically simulates the process of diamond wire sawing silicon crystals combined with the linear elastic fracture mechanics. A mathematical analysis model has been established to calculate the fracture strength of diamond wire cut silicon wafers in the light of the half-penny crack system. The effect of cutting conditions and saw wire conditions on wafers' fracture strength, and the relationship between wafers’ fracture strength and subsurface micro-crack damage depth (SSD) were studied. The study results show that the numerical calculated values are equivalent to the experimental values of the reference, which proves the correctness of this model. It is found that the wire speed and the abrasive density are positively correlated with the wafers' fracture strength. The feed rate and the maximum size difference of the abrasives are inversely correlated with the wafers' fracture strength. When the ratio of wire speed to feed rate is constant, the wafers' fracture strength has no obvious change. And if the ratio becomes larger, the wafers' fracture strength will become larger. Besides, the wafers' fracture strength is not affected by the change in the abrasive size under the condition that the maximum size difference of abrasives remains unchanged and the wire inner diameter’s change. The SSD is inversely correlated with the wafers' fracture strength. The study results of this paper can provide theoretical guidance for parameter optimization in the sawing process and reduction of wafer breakage probability.

光伏硅晶片的断裂强度受诸如切片工艺参数和锯线参数之类的因素影响。本文结合线性弹性断裂力学，对金刚石线锯硅晶体的加工过程进行了数值模拟。建立了数学分析模型，根据半分钱裂纹系统计算金刚石线切割硅片的断裂强度。研究了切削条件和锯线条件对晶片断裂强度的影响，以及晶片断裂强度与表面下微裂纹损伤深度（SSD）的关系。研究结果表明，数值计算值与参考值的实验值相当，证明了该模型的正确性。发现线速度和磨料密度与晶片的断裂强度正相关。进给速度和最大磨料尺寸差与晶片的断裂强度成反比。当线速度与进给速度之比恒定时，晶片的断裂强度没有明显变化。并且，如果该比例变大，则晶片的断裂强度变大。此外，在磨料的最大尺寸差保持不变且线材内径变化的条件下，晶片的断裂强度不受磨料尺寸变化的影响。SSD与晶片的断裂强度成反比。