Ultimate Tensile Strength Of Material Research Articles

New size number and the fracture state of concrete structure

A new size number describing the fracture state of concrete structures is developed in which the structural size and the main fracture properties of concrete are dealt with. The relation between the fracture state of concrete beams loaded in bending and the newly proposed size number is presented graphically. The shape of the stress - crack curve, which is a typical property of most quasi-brittle composites like concrete, is found to be an important factor in determining the size number together with the fracture energy, the elastic modulus and the ultimate tensile strength of materials. The influence of 'the structural size on the fracture state is also graphically presented.

Multiaxial fatigue life predictions under the influence of mean stresses: Fatemi, A. and Kurath, P.J. Eng. Mater. Technol. (Trans. ASME) Oct. 1988, 110, (4), 380–388

Time-dependent multi-configuration is a typical feature for mechanical systems such as gear trains and chain drives. As a series system, a gear train is distinct from a traditional series system, such as a chain, in load transmission path, system-component relationship, system functioning manner, as well as time-dependent system configuration. Firstly, the present paper defines time-domain series system to which the traditional series system reliability model is not adequate. Then, system specific reliability modeling technique is proposed for gear sets, including component (tooth) and subsystem (tooth-pair) load history description, material priori/posterior strength expression, time-dependent and system specific load-strength interference analysis, as well as statistically dependent failure events treatment. Consequently, several system reliability models are developed for gear sets with different tooth numbers in the scenario of tooth root material ultimate tensile strength failure. The application of the models is discussed in the last part, and the differences between the system specific reliability model and the traditional series system reliability model are illustrated by virtue of several numerical examples.