STUDY OF MICROMECHANICAL PROPERTIES OF ADHESIVE-BONDED JOINTS.
Final rept. 30 Jun 67-29 Jun 68,
GENERAL PRECISION SYSTEMS INC LITTLE FALLS N J AEROSPACE RESEARCH CENTER
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The basic purpose of this program was to demonstrate the feasibility and utility of making microstrain measurements to establish the mechanical properties of adhesives in metal-metal bonds. Loading modes were tension, compression and shear as a function of joint thickness and test temperature for selected adhesive systems. A high sensitivity capacitance-type extensometer was used to measure the deformation. The following accomplishments were achieved 1 Tensile mechanical properties of epoxy adhesives in bulk form are different from the epoxy in a metal bonded joint. 2 The tensile modulus increases with decreasing thickness, increasing strain rate, lower test temperature, higher modulus adherends. 3 The shear modulus increases with decreasing test temperature, increasing strain rate and is independent of thickness in the range of 0.004 to 0.040 inches. 4 The precision elastic limit and the viscoelastic behavior are affected by composition, test temperature and stress level. 5 Several systems showed work hardening. These techniques and results have provided new insights into the deformation characteristics of epoxy adhesives in metal bonded joints. Author
- Adhesives, Seals and Binders