标题： 关于软聚合物断裂的建模 显示英文标题

标题： On modeling fracture of soft polymers

摘要： 软聚合物是自然界和工程材料中无处不在的材料，其性质从速率无关到速率相关变化广泛。对于速率相关的软材料，当前的断裂韧性测量值在不同的加载轮廓和试样几何形状下是非唯一的。关于建模速率相关软聚合物断裂的研究局限于特定的预裂几何形状。目前尚没有普遍认可的软聚合物断裂模型。我们提出并证明，可以使用应力功的临界值作为软聚合物断裂阻力的度量。我们开发了一种损伤模型来预测软聚合物的断裂。在该模型中，临界应力功的能量部分被提议作为损伤起始准则，能够捕捉失效表面。通过广义梯度损伤框架对损伤增长进行建模。通过将模型预测与不同材料（三元乙丙橡胶EPDM、EPS25交联聚合物、丁苯橡胶SBR、天然橡胶NR和聚硼硅氧烷PBS）、各种试样几何形状和加载条件下的实验结果进行比较，验证了该断裂模型。该模型能够预测诸如脆性和延性响应以及不同断裂剖面等关键物理现象。从宏观模型参数可以预测聚合物断裂过程中的微观结构量，例如亚链解离能等。 显示英文摘要

摘要： Soft polymers are ubiquitous materials in nature and as engineering materials with properties varying from rate-independent to rate-dependent. Current fracture toughness measures are non-unique for rate-dependent soft materials for varying loading profiles and specimen geometries. Works on modeling fracture in rate-dependent soft polymers are limited to specific pre-cracked geometries. There is no generally agreed-upon model for the fracture of soft polymers. We propose and show that a critical value of stress work can be used as a measure of fracture resistance in soft polymers. We develop a damage model to predict fracture in soft polymers. In the model, the energetic part of the critical stress work is proposed as a damage initiation criterion that has the ability to capture failure surfaces. The damage growth is modeled through a generalized gradient-damage framework. The fracture model is validated for both elastomers and viscous soft polymers by comparing model predictions against experimental results for different materials (ethylene propylene diene monomer - EPDM, EPS25 vitrimer, styrene butadiene rubber - SBR, natural rubber - NR, and polyborosiloxane - PBS), a variety of specimen geometries, and loading conditions. The model can predict key physical phenomena such as brittle and ductile responses and different fracture profiles. The microstructural quantities, such as subchain dissociation energy during the fracture of polymers, can be predicted from the macroscopic model parameters.