Papers by Keyword: Torsion Strength

Abstract: This paper discusses the relationship between torsion strength and bending strength of Al₂O₃ and Si₃N₄ ceramics. Measurement of the torsion strength was carried out by a simplified torsion test method proposed by Yasuda and Tsutsumi. In this experiment, the average torsion strength was approximately 2/3 of its average bending strength for both ceramics. By estimating the characteristic strength σ₀ in Weibull distribution from the strength data, σ₀ in torsion is almost the same as that in bending, which agrees to the basic discussion in mechanics of materials. The characteristic strength σ₀ is one of the normalized strength by eliminating the effects of specimen shape, dimensions and also its stress distribution, and therefore the apparent difference between torsion and bending strengths can be explained by the difference in effective surface area (Conversely, the measured torsion strength data by the simplified method must be reasonable). It reveals that biaxial fracture in tension/compression during torsion test is equivalent to uniaxial tensile fracture by this experiment.

Abstract: In order to determine the torsion strength of non-metal materials at ambient and high temperature, a kind of equipment with inductive heating, infrared thermometer and torque loading by mechanical electrical rider was development. This equipment has advantages such as quick heating, accurate temperature test and controlling, easy controlling and continues of torque loading and test atmosphere can be controlled. The torsion strength of fireclay bricks with sample size of 40 mm × 40 mm × 230 mm, were tested separately at room temperature, 800°C, 1000°C, 1100°C and 1200°C, using this equipment. Results indicated that for the same batch of samples, the torsion strength determined by this equipment has good consistency, and mean while, it was found that the torsion strength decreased with the increase of test temperature obviously. In additional, developed equipment could be used for the determination of torsion creep at high temperature, the highest temperature of fracture under certain torque during the heating process, torque cycle fatigue failure of materials and so on.

Abstract: The calculation model for torsion strength of prestressed concrete beams (PCs) under pure torsion is deduced theoretically based on Fixed-Angle Softened Truss Model (FA-STM) and an efficient algorithm for the model is proposed. The calculated values of torsion strength and the Torque-twist curves predicted by the proposed method agree well with these obtained from tests for the two specimens available in literature. These indicate that the proposed method can not only calculate the torsion strength efficiently but can also predict the load—deformation curve of the PCs.