FW-H equations Galerkin weighted residual FEM History of engineering & technology Materials science Polyodon spathula Strength of materials bifurcations biostructure cohesive elements complex variables conformal mapping continuation methods direction field elasticity elastodynamics equivalent single-layer approach experimental test finite element method finite element modelling finite elements first-order shear deformation theory functionally graded materials gold nanowire heat conduction higher-order shear deformation theory joint static strength laminated composite plates limit points marine propeller maximum-flow/minimum-cut