Question

Consider a three-node quadratic element in one dimension with unequally spaced nodes (Fig. 2). (a) Obtain the B matrix. (b) Consider an element with x1=0, x2=1/5 and x3=1 Evaluate strain & in terms of u2 and u (u0), and check what happens when s approaches 0. (c) If you evaluate K by one-point quadrature using B EADB for same coordinates as in (b) and constrain node 1 (i.e. 0), is K invertible?

Answer 1