The element library of FRAME3D currently consists of two distinct types of beam elements, the plastic hinge and the elastofiber types, a 3-D panel zone element to model joints in steel structures, an diaphragm element to model floor slabs, and elastic springs to model foundations and compute reactions.  To see the element arrangement in a FRAME3D model, click here.

Beam Element

(1) 3-D plastic hinge element with bilinear moment-rotation relation.

(2) 3-D elastofiber element with nonlinearity modeled at the ends of the beams using fiber segments with a linear-elastic cubic-interpolated segment in between.  Fiber axial stress-strain is assumed to follow a cubic-ellipsoidal law (see user guide).

Panel Zone Element

(1) 3-D cruciform shaped panel zone element to model shear yielding in panel zones in two orthogonal directions in a beam-column joint.  Two stress-strain relations are supported - (a) bilinear (b) linear-quadratic.

Diaphragm Element

(1) 4-noded linear-elastic plane-stress element without warping.

Spring Element

(1) 2-noded linear-elastic translational or rotational spring.