Accession Number : ADA303095

Title :   Experimental Data on Single-Bolt Joints in Quasi-Isotropic Graphite/Polyimide Laminates.

Descriptive Note : Technical paper,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY RESEARCH CEN TER

Personal Author(s) : Wichorek, Gregory R.

PDF Url : ADA303095

Report Date : MAY 1982

Pagination or Media Count : 47

Abstract : The results of an experimental program to determine the bolted-joint strength and failure modes of graphite/polyimide laminates are presented. Sixteen-ply, quasi- isotropic laminates of Celion 6000/PMR-15 and Celion 6000/LARC-160 with a fiber orientation of (O/45/9O/-45)sub 2S were evaluated. Tensile and open-hole specimens were tested at room temperature to establish laminate tensile strength and net tensile strength at an unloaded bolt hole. Double-lap joint specimens with a single 4.83-mm (0.19-in.) diameter bolt torqued to 1.7 N-m (15 lbf-in.) were tested in tension at temperatures of 116 K (-250 F), 297 K (75 F), and 589 K (600 F). The joint ratios of w/d (specimen width to hole diameter) and e/d (edge distance to hole diameter) were varied from 4 to 6 and from 2 to 4, respectively. The effect of joint geometry and temperature on failure mode and joint stresses are shown. Joint stresses calculated at maximum load for each joint geometry and test temperature are reported. Five failure modes were observed for the double-lap joint specimens. For all joint ratios tested, net-tension, bearing, and shear-out stresses decreased with increasing temperature from 116 K (-250 F) to 589 K (600 F). Joint strength in net tension, bearing, and shear-out at 116 K (-250 F), 297 K (75 F), and 589 K (600 F) are given for the Celion 6000/PMR-15 and Celion 6000/LARC-160 laminates.

Descriptors :   *GRAPHITE EPOXY COMPOSITES, *POLYIMIDE PLASTICS, *BOLTED JOINTS, TENSILE STRENGTH, EXPERIMENTAL DATA, LAMINATES, STRENGTH(MECHANICS), ISOTROPISM, FASTENINGS.

Subject Categories : Laminates and Composite Materials
      Couplers, Fasteners, and Joints

Distribution Statement : APPROVED FOR PUBLIC RELEASE