A LAYERWISE BEAM ELEMENT FOR ANALYSIS OF FRAMES WITH LAMINATED SECTIONS AND FLEXIBLE JOINTS

Fiber-reinforced plastic (FRP) composites are being used currently as reinforcement for beams of conventional materials, such as concrete an d glued-laminated timber (glulam). The common assumption of plane cros s-sections through the laminate for laminated beams with dissimilar pl y stiffnesses can lead to inaccurate results, particularly for rectang ular sandwich beams with soft cores. In this paper, we extend the form ulation of a 3-node beam finite element with layerwise constant shear (BLCS) to the analysis of plane frames with rectangular laminated sect ions and flexible joints. Experimental results for sandwich beams and glulam-FRP beams are used to illustrate the accuracy of BLCS. An A-fra me with two distinct laminated cross-sections and a rigid or flexible apex-joint is analyzed with BLCS and also plane-stress and layered-she ll elements of ANSYS. The BLCS element predicts the response of the A- frame accurately and does not exhibit shear-locking.