The mastering of product reliability is essential for industrial competitiveness. If for metallic materials the topic is well-known, especially in automotive industry, Original Equipment Manufacturers are expecting strong support of their suppliers to full-fill the lack data. This paper presents a new original approach, using a micromechanical based on damage model to address the problem of reliability of Sheet Molding Compound (SMC) components. The first part demonstrates the inadequacy of the standard method of reliability on SMC material through its application on the new Peugeot 3008. In fact, the very flat S-N curve of SMC, and in general, composite materials is not appropriate for acceleration effect. The proposed model correlates the stress, damage and strength with both cycle number and slamming velocity. It emphasizes the relation between the effective distribution with the slamming velocity effect. Then, a new reliability approach based on a micromechanical fatigue/damage model was developed. The definition of new probability distributions based on damage was necessary to apply properly the stress-resistance approach. It allows taking into account the velocity effect by switching in damage space. Finally, applying this new methodology on the Peugeot 3008, leads to the definition of the optimal validation laboratory tests to ensure the reliability. Indeed, the required number of cycles to ensure reliability has been reduced significantly. Micromechanical damage reliability approach could be an efficient way to ensure the reliability of short fiber reinforcement composite components used in industrial context.

产品可靠性的掌握对于产业竞争力至关重要。如果对于金属材料来说，这个话题是众所周知的，尤其是在汽车行业，原始设备制造商希望他们的供应商提供强有力的支持，以填补短缺的数据。本文提出了一种新的原始方法，即使用基于损伤模型的微机械来解决片状模塑料（SMC）组件的可靠性问题。第一部分通过在新Peugeot 3008上的应用证明了SMC材料的标准可靠性方法不充分。实际上，SMC的SN曲线非常平坦，通常，复合材料不适合加速效果。所提出的模型将应力，损伤和强度与循环次数和撞击速度相关联。它强调了有效分布与砰击速度效应之间的关系。然后，开发了一种基于微机械疲劳/损伤模型的新可靠性方法。为了适当地应用抗应力方法，必须基于损坏定义新的概率分布。通过切换损坏空间，可以考虑速度效应。最后，将这种新方法应用于标致3008可以确定最佳验证实验室测试，以确保可靠性。实际上，确保可靠性所需的循环次数已大大减少。微机械损伤可靠性方法可能是确保在工业环境中使用的短纤维增强复合材料组件可靠性的有效方法。