Abstract: Insert assemblies of high specific strengths to reduce stress concentration at locations where Multidirectional stresses act on sandwich structures have been designed based on mapping stress distribution and failure initiation. The insert assembly comprises of insert (10, 20, 30), potting material (14, 24, 34), core (17, 27, 37), lower face plate (16, 26, 36), Upper face-plate (15, 25, 35) and attachment (13, 23, 33). The insert materials are selected from 2D woven composites, 3D thermoelastic isotropic woven composites, 3D woven composites, 3D woven composites with multiple inserts and 3D functionally gradient woven composites. Specific strengths of inserts (10, 20, 30) of present invention are higher than the inserts of prior art.