Composite Frame Research
Composite Materials Handbook Volume 6: Structural Composite Panels
This handbook is the industry standard for composites, and talks about provides information and guidance necessary to design and fabricate structural components from composite materials.
Composite Materials Handbook Vol. 6 Notes
https://cloud.wikis.utexas.edu/wiki/spaces/LHRSOLAR/pages/205226008
Insert Design Handbook
This handbook goes more in depth on how to design inserts for structural composite panels