Biomedical degradable polymer materials are widely used in medicine because of their excellent mechanical properties and degradation properties. The matching of strength change and degradation rate in the degradation process is a crucial consideration in the design of polymer devices. Establishing a strength model of the polymer degradation process can quantify the intensity evolution during the degradation process. In this research, the structural changes in the process of polymer erosion degradation are taken as the primary consideration, and the evolution of the phases of strength are reflected by the changes of structure. The concept of strength phase images is proposed. The images of the strength phase diagram are identified by the image processing method. The Near Neighbor-Boundary Enlargement Algorithm (NNBE) is put forward to identify features with the hole(block) and crack(strip) shape patterns. The strength model for different phase patterns is established. The model calculation is compared with the experimental data, and the model simulation value and the experimental value are well fitted, which indicates that the strength model and phase diagram feature extraction algorithm are feasible.

生物医学可降解聚合物材料因其优异的机械性能和降解性能而广泛用于医学领域。降解过程中强度变化和降解速率的匹配是聚合物器件设计中的关键考虑因素。建立聚合物降解过程的强度模型可以量化降解过程中的强度演变。在这项研究中，主要考虑聚合物侵蚀降解过程中的结构变化，并通过结构变化反映强度相的演变。提出了强度相位图像的概念。强度相图的图像通过图像处理方法识别。提出了一种近邻边界扩大算法（NNBE）来识别具有孔（块）和裂纹（条）形状图案的特征。建立了不同相模式的强度模型。将模型计算与实验数据进行比较，模型仿真值与实验值吻合良好，表明强度模型和相图特征提取算法是可行的。