This paper introduces a methodology that analyzes frequency changes to assess cracks with uncertain configurations. The proposed methodology employs a multimodal stress field approach, which is based on the stress dependency concerning mode shapes and boundary conditions. Existing methods based on relative frequency shifts (RFSs) fail when evaluating branched cracks, as these crack types influence the stress field across a larger segment of the beam compared to transverse cracks. Given their significant implications for structural health assessment, this study pays particular attention to cracks with L, T, and Y shapes. We developed a methodology for assessing the cracks based on severity analysis. The idea is that for the RFSs identified using measurement on the structure, the severity is similar for all modes if the correct position of the damage is found. Therefore, we compare the identified RFSs with a set of curvatures that encompass all potential locations of the damage. The damage location is identified as the point where the smallest distance between the damage severities for the contrived vibration modes is calculated. Hence, the problem of identifying the location of the damage is reduced to finding a minimum from a set of data. Through simulations, we found the natural frequencies for various crack types, generated the resulting RFSs, and found the damage locations with high accuracy. The paper demonstrates the application of the proposed framework across diverse configurations.