Predicting the failure of materials is one of the oldest problems in engineering and one of the least perfectly solved. As a result, the burden of testing is immense to prove safety in structures upon whose integrity human lives depend (certification of an airframe structures requires _104 tests of material specimens along with tests of components and structures up to entire tails, wing boxes, and fuselages). Recent developments in simulation strategies, increased computational power, and improvements in modeling tools are changing rapidly this scenario Nowadays it is possible to predict accurately the behavior until failure of composite coupon specimens and simple components through the application of bottom-up approaches
