Accession Number:

AD0628833

Title:

STRESS ANALYSIS OF ENCAPSULATION MATERIALS FOR WELDED MODULES,

Descriptive Note:

Corporate Author:

DOUGLAS AIRCRAFT CO INC SANTA MONICA CALIF MISSILE AND SPACE SYSTEMS DIV

Personal Author(s):

Report Date:

1966-02-01

Pagination or Media Count:

61.0

Abstract:

A strain-gauge load transducer, simulating an axial-leaded discrete component, was developed and fabricated by DAC to measure the magnitude and direction of axial stresses exerted by an encapsulating material. The epoxy encapsulation materials exhibited residual compressive stresses due to the initial cure of resin. Thermal cycling substantially increased these compressive stresses at the lowest temperatures. Tensile stresses were recorded during the elevated temperature phase of the test. Compressive stresses were produced as the cycle was completed forming a closed hysteresis loop, characteristic of these materials, on the stress vs. temperature curve. Within a typical cordwood welded module with component density levels of 10-30 percent, the stress levels were reduced by increasing levels of component loading. The low-density, microballoon-filled Stycast 109011 epoxy material exhibited significantly lower, more uniform tensile and compressive stresses than the medium-density, mineral-filled Hysol 42153561 9709466, Type I epoxy material within this same test configuration. Author

Subject Categories:

  • Electrical and Electronic Equipment
  • Containers and Packaging

Distribution Statement:

APPROVED FOR PUBLIC RELEASE