Skew the Element 45° and the Stiffness Grows 2.5x — Metric Tensors and Constitutive Tensor Transformation
·7 min read
In curvilinear coordinates, writing strain as covariant components means the constitutive tensor has to move too. Skip that step and every skewed element reports the wrong stiffness.
Thinner Means Stiffer — Shear Locking in Shell Elements and the MITC Tying Fix
·7 min read
A linear shell element gets stiffer, not weaker, as it thins out. The cause is one line: shear strain obtained by differentiating displacements.