Accession Number : ADP006009

Title :   Effect of Environment and Improvement Measures on Static and Fatigue Strength of Bolted CFRP-Joints,

Corporate Author : FRAUNHOFER-INST FUER BETRIEBSFESTIGKEIT DARMSTADT (GERMANY F R)

Personal Author(s) : Gerharz, J. J. ; Huth, H.

Report Date : MAR 1988

Pagination or Media Count : 16

Abstract : This paper documents effects of environments, preloading, bushings, local reinforcements and joint laminate tailoring on the efficiency of CFRP-joints. Thereby joint efficiency at static, residual and fatigue strength is considered. The laminate lay-up, the fastener system, fastener fit and clamping stresses were not changed. The material used was 914C/T300 or Fiberite 976/T300. Critical hot/wet condition expected in service reduced joint efficiency but preloading on fatigue design load level with superimposed temperature cycle per flight did not. Installation of metal bushings into fastener holes, local reinforcement by adding layers to the hole section, and joint laminate tailoring through strip design were introduced to reveal their ability to improve composite joint efficiency. They proved to be successful depending on design constraints and required joint performance. (SDW)

Descriptors :   *FATIGUE(MECHANICS), *STRENGTH(MECHANICS), *BOLTED JOINTS, BUSHINGS, CLAMPS, COMPOSITE MATERIALS, CYCLES, EFFICIENCY, FABRICATION, FASTENINGS, HIGH TEMPERATURE, HOLES(OPENINGS), INSTALLATION, JOINTS, LAMINATES, METALS, REDUCTION, REINFORCED PLASTICS, RESIDUALS, STATICS, STRESSES, TEMPERATURE.

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE