Analytical and experiment study of clearance and bearing-bypass load effects in composite bolted joints

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6419022

Naik, R V.A.

A combined analytical and experimental study is conducted to determine the effects of clearance and bearing-bypass loading for mechanically fastened joints in composites. A simple method of analysis is developed to account for the nonlinear effects of bolt-hole clearance. The nonlinear load-contact variations for clearance-fit fasteners are also measured using specially instrumented fastener. For a quasi-isotropic graphite/epoxy laminate, results show that the contact arc as well as the peak stresses around the hole and their locations are strongly influenced by the clearance. After a slight initial nonlinearity, the peak stresses vary linearly with applied load. The typical clearance levels are shown to have only a minor influence on the overall joint stiffness. Quasi-isotropic graphite/epoxy laminates (T300/5208) were tested under combined bearing and bypass loading to study failure modes and strengths. Radiographs were made after damage onset and after ultimate load to examine the failure criteria to analyze the test data. The near the bolt-hole are calculated for each test condition, and then used with appropriate failure criteria to analyze the test data. The tension data show a linear interaction for combined bearing and bypass loading with damage developing the net-tension mode and growing to failure in the same mode. Failure modes are more complex in compression.

• Research Organization: Old Dominion Univ., Norfolk, VA (USA)
• OSTI ID: 6419022
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
BOLTED JOINTS
CARBON
COMPOSITE MATERIALS
ELEMENTAL MINERALS
ELEMENTS
EPOXIDES
FAILURE MODE ANALYSIS
FASTENERS
GRAPHITE
JOINTS
MATERIALS
MINERALS
NONLINEAR PROBLEMS
NONMETALS
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
STRESS ANALYSIS
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS