PARAMETRIC STUDIES OF BEARING STRENGTH FOR FIBER METAL LAMINATES

An experimental program based on statistical design was conducted to establish a meaningful test procedure for determination of fiber/metal laminate bearing strength design allowables. The test procedures investigated are the pin-type bearing test method (ASTM E-238) and the bolt-type bearing test method, a modified method based on procedure for bearing strength determinations in plastics (ASTM D-953). Results are presented from an experimental program which measured the bearing strengths of two grades of S-2 glass fiber-based and one grade or aramid fiber-based aluminum laminates. The influences or lateral constraint and ply orientation on bearing strength and failure mode are observed. The bolt-type bearing test method which combines the attributes of two aforementioned methods is recommended. The study also showed that bearing properties of edge distance ratio equals to 2 can be predicted by correlation with the aluminum volume fraction in fiber-reinforced aluminum laminates. In addition, diagrams of joint structural efficiency shown to be comparable with aluminum alloy sheets have been established.