Many problems have an ideal limit (e.g., perfectly plastic, no cracks, infinite grain size). Compute that limit first. Then see how your full solution deviates. If your full solution does not reduce to the simple case under limiting assumptions, it’s wrong.
Because the problems often require multi-step derivations or the application of specific empirical constants, having a solution manual becomes an essential "sanity check" for students working through the problem sets. Key Topics Covered in the Solution Manual mechanical behavior of materials courtney solution manual