Senior scientist, Lockheed Palo Alto Research Laboratory, Palo Alto, CA
Staff engineer, Lockheed Missiles and Space Company, Inc., Sunnyvale, CA
The stress state in graphite epoxy tension specimens subjected to pure tension, to combined tension, and to out-of-plane bending is analyzed. A finite element solution technique is used that includes full representation of the wedge-action grip mechanism of the testing machine as well as end tabs bonded to the test laminate with a finite thickness adhesive layer. Results of the study indicate that stresses are generally lower for the tension specimens with tapered tab geometry. Peak stresses in the specimens are found to be sensitive to tab length. thickness, and layer orientation, as well as test laminate stiffness. Out-of-plane specimen bending resulting from grip misalignment also resulted in significant increases in the specimen stresses.
Paper ID: CTR10785J