Fatigue life estimation is one of the most important design considerations in mechanical parts which are subjected to alternating loads. When loads act along several axes, multiaxial fatigue approach should be used to obtain more accurate results than uniaxial fatigue method. In this paper stress analysis of the steel shaft of a high speed microgenerator rotor with 47750 rpm and 100kW is carrie...

The Welding in cold formed areas is not only an open question for statically loaded sections (brittle fracture) but also for dynamically loaded structures (fatigue resistance). A lot of structures are subjected to dynamic loadings and unfortunately very little information about the influence of welding in the cold formed areas on fatigue resistance is available. In order to establish the fatigu...

Purpose: The purpose of this paper was to find relationship between the degree of strength degradation caused by fatigue and the changes of ultrasonic wave characteristics such as wave velocity and damping coefficient. Design/methodology/approach: Epoxy-glass composites were subjected to oscillatory bending loadings with constant deflection. During fatigue procedure the force needed to achieve ...

We report on the mechanical fatigue behavior of printed, organic, thin-film transistors (OTFTs) based on a polymer semiconductor, investigated by repeatedly applying strain to the flexible OTFT devices and assessing their electrical characteristics after 60,000 bending cycles. As part of our investigation, we established that the rates of reduction in source/drain currents in the OTFT device de...

The hardmetal cutting tools used in machining are submitted to extreme conditions in terms of temperature and mechanical loading. A better understanding of the failure of cutting tools and capability to predict tool life are key factors in the development of new tool materials with improved mechanical behaviour. Main failure mechanisms are wear, thermal–mechanical fatigue and brittle fracture. ...

The flexural fatigue behavior of hybrid composite rods comprised of unidirectional carbon and glass fibers was investigated. Damage was evaluated by monitoring stiffness loss as a function of cycles, and bending fatigue failure was defined in terms of strength retention. The acoustic emission technique and microscopic examination were used to characterize damage progression and failure mechanis...

In the present paper the effect of defects (viz. pits, gouges and oxide inclusions) will be reported. Although certain defects were uniformly distributed over the specimen surface, the majority of all fractures started in the edge region. An explanation to this behaviour is presented in terms of stress enhancement in the edge regions due to edge deflections.

Introduction Studies document rod fracture in pedicle subtraction osteotomy (PSO) settings where disk spaces were preserved above or adjacent to the PSO. This study compares the multidirectional bending rigidity and fatigue life of PSO segments with or without interbody support. Methods Twelve specimens received bilateral T12-S1 posterior fixation and L3 PSO. Six received extreme lateral interb...

This paper proposes a method of evaluating the fatigue life of a refrigeration compressor reed valve, given the applied stresses as might be computed by a valve simulation. Mean and alternating values of equivalent stresses (e.g. Von Mises) are plotted in the Haigh diagram. Various choices of models are considered for the safe area of the diagram. This method takes into account surface finish, ...