Hi, thank you very much for this great video very detailed and well explained. Please could you help by explaining why the tetrahedron 4-noded and the triangular 3-noded finite elements do not require numerical integration while the 8-noded quadrilateral finite element does.
Thanks for your comment. Numerical integration is used to solve complex integration. For the case of 3 Noded triangular element, you are dealing with constant strain triangle (CST), therefore, you are simply integrating a constant number.
Thank you very much ! I was wondering for shear locking, you said "linear element cannot represent that curved edges..." but fully integrated element are no more linear ?
Linear elements can be both fully integrated or have reduced integration. Full integration will only cause shear locking, to avoid it we can either use linear with reduced integration or higher order with full or reduced integration.