Green hydrogen is emerging as one of the most promising alternatives to replace fossil fuels. While hydrogen gas has a good energy density by weight, its poor energy density by volume requires it to be stored under high pressure for commercial use. The hydrogen infrastructure developed to handle this high pressure hydrogen contains multiple components made of polymers such as O-rings, pipes, hoses, and inner liners of storage tanks. Although polymers do not react chemically with hydrogen gas, they undergo a mechanical failure when high pressure hydrogen gas is suddenly depressurized. This phenomenon known as ‘rapid decompression failure’ (RDF) occurs due to the diffusion of hydrogen through polymer and getting trapped inside preexisting cavities or voids.

In this paper, a continuum mechanics-based coupled diffusion–deformation-damage model was developed to predict the hydrogen distribution, stress distribution, and damage propagation inside the polymer while it undergoes rapid decompression failure. The polymer was modeled as a hyperelastic material because it represents the nonlinear material response observed in uniaxial tensile tests perfectly. The effect of hydrogen diffusivity, preexisting cavity size, cavity location, applied hydrogen pressure, and depressurization rate on damage initiation was studied. It was found that the coefficient of diffusion plays an important role in damage initiation and damage was mostly concentrated in the inside areas rather than near the surface. Experiments were conducted with ethylene propylene diene monomer (EPDM) which agreed well with the predicted trends using the given model. The effect of adding carbon black and silica filler particles and plasticizer to the pure EPDM polymer was also studied. It was found that damage during RDF decreases with the addition of fillers, but increases with the addition of the plasticizer. Finally, the damage evolution in the presence of two cavities was also studied, and was found that the interaction of stress fields around the cavities alters the damage occurring during RDF.

绿色氢正在成为替代化石燃料的最有前途的替代品之一。虽然氢气具有良好的重量能量密度，但其较差的体积能量密度需要在高压下储存才能用于商业用途。为处理这种高压氢气而开发的氢气基础设施包含多个由聚合物制成的部件，例如 O 形环、管道、软管和储罐内衬。尽管聚合物不与氢气发生化学反应，但当高压氢气突然减压时，它们会发生机械故障。这种称为“快速减压失效”(RDF) 的现象是由于氢通过聚合物扩散并被困在预先存在的空腔或空隙中而发生的。

在本文中，开发了一种基于连续介质力学的耦合扩散-变形-损伤模型，以预测聚合物在经历快速减压失效时的氢分布、应力分布和损伤传播。聚合物被建模为超弹性材料，因为它完美地代表了在单轴拉伸试验中观察到的非线性材料响应。氢气扩散率、预先存在的空腔尺寸、空腔位置、施加的氢气压力和减压的影响研究了损伤发生率。结果发现，扩散系数在损伤萌生中起着重要作用，损伤主要集中在内部区域而不是表面附近。使用三元乙丙橡胶 (EPDM) 进行实验，结果与使用给定模型预测的趋势非常吻合。还研究了向纯 EPDM 聚合物中添加炭黑和二氧化硅填料颗粒和增塑剂的效果。发现 RDF 过程中的损坏随着填料的添加而减少，但随着增塑剂的添加而增加。最后，还研究了存在两个空腔时的损伤演化，发现空腔周围应力场的相互作用改变了 RDF 过程中发生的损伤。