Accession Number : ADA261698


Title :   Failure Considerations in Composite Systems Based on 3D Micromechanical Stress Fields: Part A


Descriptive Note : Final technical rept.


Corporate Author : UTAH UNIV SALT LAKE CITY DEPT OF MATHEMATICS


Personal Author(s) : Folias, E S


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a261698.pdf


Report Date : Dec 1992


Pagination or Media Count : 326


Abstract : In this investigation, a systematic 3D micromechanics approach is used to model a composite. The fibers are assumed to be cylindrical inclusions which are periodically embedded into a matrix plate. A three dimensional analysis is used in order to capture any edge effects which may be present. A set of fundamental key problems has been identified and their respective solutions for the displacement and stress fields are then used in order to provide us with some answers to the following fundamental questions: transverse strength, longitudinal strength, residual stresses due to thermal expansion mismatch, modeling of fiber matrix interface, edge effects. The 3D results are then used to first identify critical locations where failure, due to fracture, is most likely to initiate and second to derive fracture criteria for crack initiation at the local level. The criteria reveal the dependence of the composite strength on the material properties, the local cell geometry, the ratio of the fiber volume fraction, the ratio of fiber radius to fiber length and finally the applied mechanical and or thermal loads.


Descriptors :   *STRESSES , *COMPOSITE MATERIALS , *FAILURE , *MICROMECHANICS , *THREE DIMENSIONAL , RATIOS , VOLUME , FIBERS , EDGES , CRACKS , FRACTURE(MECHANICS) , TRANSVERSE , EXPANSION , GEOMETRY , THERMAL EXPANSION , LENGTH , RESIDUALS , PLATES , INCLUSIONS , STRENGTH(MECHANICS) , DISPLACEMENT , LOADS(FORCES) , MODELS , INTERFACES , CELLS , MATERIALS


Subject Categories : Laminates and Composite Materials
      Textiles
      Mechanics
      Thermodynamics


Distribution Statement : APPROVED FOR PUBLIC RELEASE