Effect of Compressive Stress on Multiaxial Loading Fracture of Alumina Tubes

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J. Korean Ceram. Soc. > Volume 28(10); 1991 > Article

Journal of the Korean Ceramic Society 1991;28(10): 810.

알루미나 튜브의 복합하중 파괴에 미치는 압축응력의 영향

김기태, 서정

포항공과대학 기계공학과

Effect of Compressive Stress on Multiaxial Loading Fracture of Alumina Tubes

ABSTRACT

Fracture responses of Al2O3 tubes were investigated for various loading paths under combined tension/torsion. The fracture criterion did not depend on loading paths. Fracture angles agreed well with the maximum tensile stress criterion. As the loading condition approaches a shear dominant state, the tensile principal stress at fracture increases compared to the uniaxial fracture strength. By using the Weibull modulus obtained from tension and torsion tests, the Weibull statistical fracture strengths were compared with experimental data. This comparison suggests that fracture may occur at the surface of the specimen when tensile stress is dominant, but within the volume of the specimen when shear stress is dominant. The Weibull fracture strength increased as the loading conition approached a shear dominant state, but underestimated compared to experimental data. Finally, a new fracture criterion was proposed by including the effect of compressive principal stress. The proposed criterion agreed well with experimental data of Al2O3 tubes not only at combined tension/torsion but also at balanced biaxial tension.