Metallic materials - Fatigue testing - Force controlled thermo-mechanical fatigue testing method

Piston is one of the most stressed components of an engine. In this paper, a 1/2 3-D solid model of a new designed piston was built by using ANSYS software. The stable stress distribution and the deformation under the thermo-mechanical coupling condition were firstly calculated. Calculating results indicates that the maximum stress concentration is at the upper end of piston pin boss inner hole, and is mainly caused by the peak pressure of the fuel gas. Then the finite element dynamic analysis was conducted based on the mechanical fatigue testing method, and the mechanical fatigue life-span was calculated. All these work indicate that the design of the piton is reasonable.

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Metallic materials. Fatigue testing. Strain-controlled thermomechanical fatigue testing method

10.3403/30096503u ◽

2015 ◽

Keyword(s):

Fatigue Testing ◽

Thermomechanical Fatigue ◽

Metallic Materials ◽

Testing Method

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Accelerated mechanical fatigue interconnect testing method for electrical wire bonds

tm - Technisches Messen ◽

10.1515/teme-2017-0131 ◽

2018 ◽

Vol 85 (4) ◽

pp. 213-220 ◽

Cited By ~ 4

Author(s):

Bernhard Czerny ◽

Golta Khatibi

Keyword(s):

Failure Mode ◽

High Performance ◽

Fatigue Testing ◽

High Reliability ◽

Rapid Screening ◽

Shear Stresses ◽

Mechanical Fatigue ◽

Testing Method ◽

Wire Bonds ◽

Lift Off

AbstractEvery new development in device performance and packaging design, can drastically affect the reliability of devices due to implementation of new materials and design changes. High performance and high reliability demands in power electronics over several decades and a short time to market development, raise the need for very fast reliability testing methods. In this study a mechanical fatigue testing method is presented for evaluating the interfacial fatigue resistance of heavy Al wire bonded interconnects in high power modules. By separating the concurrent thermal, mechanical and environmental failure mechanisms a selective investigation of the desired failure mode is possible. The setup is designed to reproduce the thermo-mechanical shear stresses by mechanical means, while provoking the same lift-off failure mode as in power cycling tests. With a frequency variable test setup of a few Hz up to several kHz, measurements from 103up to 108loading cycles and determining the influence of the testing frequency on the fatigue life are possible. A semi-automated bond wire fatigue tester operating at 60 kHz is presented which is suitable for rapid screening and qualification of a variety of wire bonds at the stages of development and during the production.

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