skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Thermoelastic determination of individual stress components in loaded composites

Abstract

An experimental-numerical hybrid method is developed for determining the individual stresses in orthotropic composites from measured thermoelastic information. This includes evaluating the thermoelastic calibration coefficients, effective processing of the noisy measured data, and separating the stress components at nonboundary locations. The method is illustrated experimentally by application to a uniaxially loaded fiber-reinforced composite plate containing a central circular hole. 39 refs.

Authors:
; ; ;  [1]
  1. (Jilin University of Technology, Changcun (China) Detroit Diesel Co., MI (United States) Wisconsin, University, Madison (United States))
Publication Date:
OSTI Identifier:
6957380
Resource Type:
Journal Article
Resource Relation:
Journal Name: Experimental Mechanics; (United States); Journal Volume: 32:2
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; COMPOSITE MATERIALS; STRESS ANALYSIS; FIBERS; FINITE ELEMENT METHOD; GLASS; REINFORCED PLASTICS; THERMOELASTICITY; CALCULATION METHODS; ELASTICITY; MATERIALS; MECHANICAL PROPERTIES; NUMERICAL SOLUTION; PETROCHEMICALS; PETROLEUM PRODUCTS; PLASTICS; REINFORCED MATERIALS; SYNTHETIC MATERIALS; TENSILE PROPERTIES; 360603* - Materials- Properties

Citation Formats

Feng, Z., Zhang, D., Rowlands, R.E., and Sandor, B.I. Thermoelastic determination of individual stress components in loaded composites. United States: N. p., 1992. Web. doi:10.1007/BF02324718.
Feng, Z., Zhang, D., Rowlands, R.E., & Sandor, B.I. Thermoelastic determination of individual stress components in loaded composites. United States. doi:10.1007/BF02324718.
Feng, Z., Zhang, D., Rowlands, R.E., and Sandor, B.I. 1992. "Thermoelastic determination of individual stress components in loaded composites". United States. doi:10.1007/BF02324718.
@article{osti_6957380,
title = {Thermoelastic determination of individual stress components in loaded composites},
author = {Feng, Z. and Zhang, D. and Rowlands, R.E. and Sandor, B.I.},
abstractNote = {An experimental-numerical hybrid method is developed for determining the individual stresses in orthotropic composites from measured thermoelastic information. This includes evaluating the thermoelastic calibration coefficients, effective processing of the noisy measured data, and separating the stress components at nonboundary locations. The method is illustrated experimentally by application to a uniaxially loaded fiber-reinforced composite plate containing a central circular hole. 39 refs.},
doi = {10.1007/BF02324718},
journal = {Experimental Mechanics; (United States)},
number = ,
volume = 32:2,
place = {United States},
year = 1992,
month = 6
}
  • Laminated composite materials tend to fail differently under tensile or compressive load. Under tension, the material accumulates cracks and fiber fractures, while under compression, the material delaminates and buckles. Tensile-compressive fatigue may cause either of these failure modes depending on the specific damage occurring in the laminate. This damage depends on the stress ratio of the fatigue loading. Analysis of the fatigue behavior of the composite laminate under tension-tension, compression-compression, and tension-compression had led to the development of a fatigue envelope presentation of the failure behavior. This envelope indicates the specific failure mode for any stress ratio and number ofmore » loading cycles. The construction of the fatigue envelope is based on the applied stress-cycles to failure (S-N) curves of both tensile-tensile and compressive-compressive fatigue. Test results are presented to verify the theoretical analysis. 8 refs.« less
  • This paper examines the problem of determining the number of principal components in the products from thermodesorption/mass spectroscopy (TDMS) of isopropylbenzene on aluminosilicates, and in the products of TDMS from tetralin on alumina-nickel-molybdenum zeolitic catalysts. Aluminosilicate catalysts are used extensively in the catalytic cracking of various petroleum cuts and alumina-nickel-molybdenum zeolitic catalysts are used in petroleum refining and petrochemical processes such as hydrocracking, hydrotreating, and hydrodesulfurization. The number of principal components in products from the catalytic conversion of individual hydrocarbons is calculated: 4-5 components in the products of TDMS of isopropylbenzene, and 7-8 components in the conversion of tetralin onmore » alumina-nickel-molybdenum catalysts.« less
  • A procedure is described for the spectrographic determination of N/sup 15/ in amino acid mixtures. The procedure is simple and does not require the separation of amino acids from other nitrogen-containing substances. (C.H.)
  • A micromechanics model is presented to predict thermoelastic properties of composites reinforced with plain weave fabrics. A representative volume element is chosen for analysis and the fiber architecture is described by a few simple functions. Equations are developed to calculate various phase fractions from geometric parameters that can be measured on a cross section. Effective elastic moduli and effective thermal expansion coefficients are determined under the assumption of uniform strain inside the representative volume element. The resulting model is similar to the classical laminated theory, and hence is easier to use than other models available in the literature. An experimentalmore » correlation is provided for a number of Nicalon SiC/CVI SiC and Graphite/CVI SiC composite laminates.« less