This paper reviews the capabilities of a plasticity-induced crack-closure model to predict fatigue lives of metallic materials using “small-crack theory” for various materials and loading conditions. Crack tip constraint factors, to account for three-dimensional stateof-stress effects, were selected to correlate large-crack growth rate data as a function of the effective-stress-intensity factor...

The problem of fatigue-crack-growth in a rotating disc at different crack orientation angles is studied by using an automated numerical technique, which calculates the stress intensity factors on the crack front through the three-dimensional finite element method. Paris law is used to develop the fatigue shape of initially semi-elliptical surface crack. Because of needs for the higher mesh dens...

In this paper, the effect of interference fit on fatigue life of holed plate of mechanical joints was investigated experimentally. Fatigue tests were carried out on the holed specimens of Al-alloy 7075-T6 alloy. The interference fit process consists of force fitting a fastener into the hole with a negative clearance (diameter of the fastener is larger than of the hole) that produces beneficial ...

In the aerospace and aviation sectors, the damage tolerance concept has been applied widely so that the modeling analysis of fatigue crack growth has become more and more significant. Since the process of crack propagation is highly nonlinear and determined by many factors, such as applied stress, plastic zone in the crack tip, length of the crack, etc., it is difficult to build up a general an...

This paper evaluates the effects of microbiologically influenced corrosion (MIC) on fatigue-crack growth of candidate materials useful in expanding bio-ethanol usage, including a storage-tank steel (ASTM A36) and two pipeline steels (API 5L X52 and X70). The microbiological species sampled and cultivated from an ethanol fuel production stream are responsible for both acetic acid and hydrogen su...

A cohesive fatigue-crack nucleation and growth model for ferroelectric materials under electro-mechanical loading is presented. The central feature of the model is a hysteretic cohesive law which couples the mechanical and electrical fields. This law can be used in conjunction with general constitutive relations of bulk behavior, possibly including domain switching, in order to predict fatigue ...

In the present note, the effects of two typical organic solvents, ethanol (95~) and carbon tetrachloride (99~) , on the fatigue crack propagation rates in PMMA are discussed. Fracture mechanics which has been applied successfully to fatigue crack propagat ion in bo th metallic and polymeric sheet materials [1-4] in air is adopted in the present environmental fatigue analyses. The generalized fa...

This research comprises a study of the effect of heat treatment on fatigue behavior of (A193-51T-B7) alloy steel. Two heat treatment processes were conducted, namely, annealing and quenching followed by tempering at 200C. All fatigue tests were carried out using a rotary bending machine with constant stress ratio, R=-1. The eddy current probe was used to measure the crack length propagation. Fr...

A model has been created to allow the quantitative estimation of the fatigue crack growth rate in steels as a function of mechanical properties, test–specimen characteristics, stress–intensity range and test–frequency. With this design, the remarkable result is that the method which is based on steels, can be used without modification, and without any prior fatigue test, to estimate the crack g...

In the present investigation, an attempt has been made to use “exponential model” in the prediction of fatigue life without integrating the fatigue crack growth rate curve (FCGR). The obtained results are compared with experimental crack growth data obtained for 2024-T351 aluminum alloy for four bending V-Charpy specimens under constant amplitude loading in stress ratio range from 0.1 to 0.3 an...