Thermomechanical fatigue lifetime evaluation of solder joints in power semiconductors using a novel energy based modeling

Purpose This paper aims to establish a more accurate model for lifetime estimation. Design/methodology/approach Finite element model simulation and experimental tests are used to enhance the lifetime prediction model of the solder joint. Findings A more precise model was found. Originality/value It is confirmed that the paper is original.

Typical Errors Analysis in Frequency Response Function Measurement

FRF measurements can suffer from various errors. The effect of deterministic errors become more prominent compared to random errors in FRF measurement. Excitation and sensor misalignment is the most common source of deterministic error, so mathematic model is established and the effect on FRF estimation was analyzed for senor and excitation misalignment situations. Finite element model simulation reveals that misalignment error can have the least effect on the dominant FRFs and a stronger effect on lesser FRFs, beside that it also results in the appearance of false peaks in the measured FRFs.

Finite Element Study on Influence of Ring Beam at Top Window Sill Elevation on Temperature Effect of Masonry

This paper mainly studies on the problem of the temperature cracks of the concrete perforated brick masonry structure by finite element model simulation and the stress distribution of masonry at the top window sill elevation under temperature difference effect. Analysis the influence of setting ring beam at the top window sill elevation on temperature stress of masonry, Summed up some measures about control and prevention of masonry temperature cracks at the top window sill elevation, it can be referenced for concrete perforated brick masonry structure design and construction.