Accession Number : AD0444163


Title :   FACTORS CONTROLLING THE STRENGTH OF COMPOSITE BODIES (INTERPHASE FRACTURING OF COMPOSITE BODIES)


Descriptive Note : Quarterly progress rept. no. 1, 17 Feb-17 May 1964


Corporate Author : MATERIALS RESEARCH LAB INC RICHTON PARK IL


Personal Author(s) : Ripling, E J ; Mostovoy, S


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/444163.pdf


Report Date : 17 May 1964


Pagination or Media Count : 18


Abstract : The factors that control the fracture toughness of adhesive joints at ambient temperature and humidity are the adherend material, its surface finish and geometry, the adhesive composition and curing procedure, the bond thickness, the loading rate and resulting crack velocity and fracture type. Of major concern is the fracture type and the range of crack velocities associated with each type. The major effort during this first quarterly period was directed toward assembling and evaluating high strain rate recording equipment. It is possible by means of an oscilloscope to record load-deflection, deflection-time, load-time and crack length-time simultaneously up to and during crack propagation. The fracture surface can be marked with a ripple pattern of known frequency so that the cracking rate can be measured over microscopic distances. Preliminary test were made on a stoichiometric composition of an epoxy resin and hardener system. The crack extension force for a running crack is 75 % that of a stationary crack, and aluminum bond surface finished of 10 and 25 micro-inch (rms) produce identical toughness.


Descriptors :   *COMPOSITE MATERIALS , *BONDED JOINTS , ADHESIVE BONDING , ADDITIVES , HARDENING , ALUMINUM


Subject Categories : Laminates and Composite Materials
      Adhesives, Seals and Binders


Distribution Statement : APPROVED FOR PUBLIC RELEASE