This study presents a nonordinary state-based (NOSB) peridynamic (PD) modeling of creep deformation and damage. The force density vectors in PD equilibrium equations are derived by considering the Liu and Murakami creep model with a damage parameter. The bond-associated (BA) deformation gradient is derived by using the PD differential operator (PDDO). Traction and displacement boundary conditions are directly imposed through a novel strategy while solving for the strong form of PD equilibrium equations. The PD form of traction components enables the imposition of traction conditions in the actual “boundary layer” region without any unphysical displacement kinks near the boundaries. The approach is validated under uniaxial and 2D plane stress assumptions by considering creep deformation due to constant stress at high temperatures. The creep strain predictions are in excellent agreement with the experimental data and analytical solutions. Subsequently, creep crack growth in a compact tension (CT) specimen is simulated by using the damage variable in Liu and Murakami constitutive model.

本研究提出了蠕变变形和损伤的基于非常态 (NOSB) 的近场动力学 (PD) 模型。 PD 平衡方程中的力密度矢量是通过考虑具有损伤参数的 Liu 和 Murakami 蠕变模型而导出的。键相关 (BA) 变形梯度是通过使用 PD 微分算子 (PDDO) 导出的。牵引力和位移边界条件是通过一种新颖的策略直接施加的，同时求解强形式的 PD 平衡方程。 PD 形式的牵引组件能够在实际“边界层”区域施加牵引条件，而不会在边界附近出现任何非物理位移扭结。通过考虑高温下恒定应力引起的蠕变变形，该方法在单轴和二维平面应力假设下得到了验证。蠕变应变预测与实验数据和解析解非常吻合。随后，使用 Liu 和 Murakami 本构模型中的损伤变量模拟紧凑拉伸 (CT) 样本中的蠕变裂纹扩展。