损伤力学（破坏力学）是有关材料受损的形式以及其建模，以便有助于对材料开始受损、损伤扩散及断裂进行工程的预测，而不需要进行实务上复杂的显微组织分析。

损伤力学是典型用工程方式针对复杂现象建模的例子，引用美国机械学家Dusan Krajcinovic的说法「人们常认为工程研究的终端目标不是对现象有更深入的了解，而是提供一个可以应用在设计上的预测工具」。损伤力学是工程力学的一环，以连续介质力学为基础。

大部份损伤力学的工作都会用状态变量表示材料硬度上的受损．以及在考虑热及机械的负载及材料老化后，材料还可使用的寿命。状态变量要是可以量测的，例如裂纹密度，或是一些巨观的量值，例如硬度、热膨胀系数、残余寿命等。状态变量有共轭的热力学力来产生进一步的损伤。一开始材料是完好的，有一个损伤启动的准则预测材料开始受损，除非材料开始受损，不然不会出现自发性的损伤演进，因此需要一个损伤演进的模型。在较类似塑性的损伤模型下，损伤演进是由析出硬化来控制，另一方面微观力学的损伤模型可以在没有额外材料特性的情形下，预测材料受损的开始以及损伤的演进。

Damage mechanics is concerned with the representation, or modeling, of damage of materials that is suitable for making engineering predictions about the initiation, propagation, and fracture of materials without resorting to a microscopic description that would be too complex for practical engineering analysis. Damage mechanics illustrates the typical engineering approach to model complex phenomena. To quote Dusan Krajcinovic, "It is often argued that the ultimate task of engineering research is to provide not so much a better insight into the examined phenomenon but to supply a rational predictive tool applicable in design". Damage mechanics is a topic of applied mechanics that relies heavily on continuum mechanics. Most of the work on damage mechanics uses state variables to represent the effects of damage on the stiffness and remaining life of the material that is damaging as a result of thermomechanical load and ageing. The state variables may be measurable, e.g., crack density, or inferred from the effect they have on some macroscopic property, such as stiffness, coefficient of thermal expansion, remaining life, etc. The state variables have conjugate thermodynamic forces that motivate further damage. Initially the material is pristine, or intact. A damage activation criterion is needed to predict damage initiation. Damage evolution does not progresses spontaneously after initiation, thus requiring a damage evolution model. In plasticity like formulations, the damage evolution is controlled by a hardening function [but this requires additional phenomenological parameters that must be found through experimentation, which is expensive, time consuming, and virtually no one does]_ref ?. On the other hand, micromechanics of damage formulations are able to predict both damage initiation and evolution without additional material properties.