Abstract: A method an apparatus for testing shear strain response of a test specimen having a thick adhesive bond line is disclosed. Method and apparatus permit the use of readily available clip-on extensometers. The apparatus and method may include the use of knife edges secured to each of two adherend components on a standard ASTM D 5656 thick adherent test specimen.

Abstract: A system and method for assisting in real time alignment of an alignment specimen within a load frame. In one implementation an instrumented alignment specimen is used to provide information from which the deflection of the specimen at various points along the specimen can be determined. The deflection information is then used to calculate deflection values in X, Y and Z coordinate axes in real time. The deflection values are then scaled by a desired factor and then used to generate a three dimensional representation of the alignment specimen. This produces a slightly exaggerated, three dimensional representation of the alignment specimen illustrating its deformation as a result of concentric and/or angular misalignment of the lower head of the load frame relative to the upper head.

Abstract: A test method for visual documentation of micro-cracks during tensile coupon testing includes the steps of: assembling a test unit; inserting a carbon-reinforced composite specimen having a prepared edge into the tensile coupon testing machine; illuminating the prepared edge of the specimen with a camera strobe light and a microscope light; applying a tensile load to the specimen; and capturing images (at 10% increments of the expected failing stress) of the prepared edge of the specimen with a digital camera that is attached to a stereomicroscope. Using the test method of the present invention photographic documentation of the formation and growth of micro-cracks in carbon-reinforced composite materials under tensile load is possible. The obtained data may be used to avoid or limit fatigue failure of carbon-reinforced structures used, for example, in the aerospace industry, for example, in spacecrafts and advanced military aircraft.