In the field of continuous fiber reinforced polymers (FRP), micromechanical analyses have established as a powerful tool for determining the effective properties of composites. Representative volume elements (RVE) consisting of fibers, matrix and a fiber-matrix interface are generated as part of finite element simulations (FEM). In damage analysis, crack initiation and crack growth depend largely on the material models used. Especially for the interface, the determination of the input parameters is associated with considerable experimental effort. Furthermore, heterogeneous multiaxial stress states are present within the matrix , which contribute to a considerable reduction in the strength of the matrix, particularly under hydrostatic tension. To investigate damage mechanisms in FRP, a micromechanical FEM model is presented which considers the matrix behavior under these multiaxial stress states by means of elasto-plastic material and continuum mechanical damage models. Furthermore, the interface is described using a generalized traction separation law. The required material parameters are determined by (micro) mechanical tests on epoxy resin specimens and single fiber composites e.g. using the single fiber pullout test. The presented procedure is applied to composites with few single fibers as well as to conventional RVEs in order to make statements about damage phenomena in FRP. Furthermore, an experimental setup for the validation of the simulation is presented. The results show the influence of fiber spacing, matrix and interphase properties on the location of crack initiation in a continuous fiber reinforced polymer under transverse loading, especially including the effect of multiaxial stresses inside the matrix.