Test for Material Fatigue

1993 ◽  
pp. 63-66
Author(s):  
W. Lemm
Keyword(s):  
Material Fatigue

Estimation of Service Life of Mechanical Engineering Components

2019 ◽  
Vol 799 ◽  
pp. 71-76
Author(s):  
Oskars Linins ◽  
Ernests Jansons ◽  
Armands Leitans ◽  
Irina Boiko ◽  
Janis Lungevics
Keyword(s):  
Service Life ◽  
Service Time ◽  
Surface Texture ◽  
Mechanical Engineering ◽  
Friction Pair ◽  
Theory Of Elasticity ◽  
New Approach ◽  
Material Fatigue ◽  
Texture Parameters ◽  
3D Surface Texture

The paper is aimed to the methodology for estimation of service life of mechanical engineering components in the case of elastic-plastic contact of surfaces. Well-known calculation methods depending on physics, theory of probability, the analysis of friction pair’ shape and fit include a number of parameters that are difficult or even impossible to be technologically controlled in the manufacturing of mechanical engineering components. The new approach for wear rate estimation using surface texture parameters as well as physical-mechanical properties and geometric parameters of components is proposed. The theoretical part of the calculations is based on the 3D surface texture principles, the basics of material fatigue theory, the theory of elasticity and the contact mechanics of surfaces. It is possible to calculate the service time of the machine, but the process of running-in of the components is relatively short (less than 5%), therefore, the service time is mainly determined by a normal operating period, which also was used to evaluate this period. The calculated input parameters are technologically and metrologically available and new method for calculating the service time can be used in the design process of the equipment. The results of approbation of the method for estimation service time of mechanical engineering, which prove the applicability of mentioned method, are offered as well.

Matching Relationship between Shaft Material and Fatigue Properties under Complex Loading Condition

2012 ◽  
Vol 500 ◽  
pp. 484-488
Author(s):  
Wo Bo Zhang
Keyword(s):  
Fatigue Strength ◽  
Carbon Steel ◽  
Loading Condition ◽  
Influence Factors ◽  
Complex Loading ◽  
Fatigue Properties ◽  
Material Fatigue ◽  
Relevant Factors

According to analyzing the influence factors of shaft fatigue properties, the matching relationships between fatigue properties and shaft material as well as other relevant factors have been investigated. And the matching relationships have been demonstrated via experimentation. A useful method is established to enhance material fatigue toughness. Considering the aspects of safety, economy and the requirement of fatigue strength, when the dimension of the structure could not be changed, the fatigue properties can be improved via increasing the fillet of the shaft. And 45 carbon steel is a highly recommended shaft material.

Evaluation and prediction of material fatigue characteristics under impact loads: review and prospects

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xintian Liu ◽  
Que Wu ◽  
Shengchao Su ◽  
Yansong Wang
Keyword(s):  
Mechanical Properties ◽  
Design Methodology ◽  
Mechanical Performance ◽  
Impact Load ◽  
Impact Loads ◽  
Content Type ◽  
Material Fatigue ◽  
Mechanical Properties Of Materials ◽  
Fatigue Characteristics ◽  
Properties Of Materials

PurposeThe properties of materials under impact load are introduced in terms of metal, nonmetallic materials and composite materials. And the application of impact load research in biological fields is also mentioned. The current hot research topics and achievements in this field are summarized. In addition, some problems in theoretical modeling and testing of the mechanical properties of materials are discussed.Design/methodology/approachThe situation of materials under impact load is of great significance to show the mechanical performance. The performance of various materials under impact load is different, and there are many research methods. It is affected by some kinds of factors, such as the temperature, the gap and the speed of load.FindingsThe research on mechanical properties of materials under impact load has the characteristics as fellow. It is difficult to build the theoretical model, verify by experiment and analyze the data accumulation.Originality/valueThis review provides a reference for further study of material properties.

scholarly journals Comparison of Experimental Thermal Methods for the Fatigue Limit Evaluation of a Stainless Steel

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 677 ◽  
Author(s):  
Mauro Ricotta ◽  
Giovanni Meneghetti ◽  
Bruno Atzori ◽  
Giacomo Risitano ◽  
Antonino Risitano
Keyword(s):  
Fatigue Limit ◽  
Rapid Determination ◽  
Mechanical Energy ◽  
Thermal Methods ◽  
Aisi 304L ◽  
Material Fatigue ◽  
Static Tensile ◽  
Energy Dissipated ◽  
Material Temperature

This paper regards the rapid determination of fatigue limit by using thermal data analysis. Different approaches available in the literature to estimate the fatigue limit of cold-drawn AISI 304L bars are analyzed and compared, namely, temperature- and energy-based methods. Among the temperature-based approaches, the Risitano Method (RM) and the method based on material temperature evolution recorded during a static tensile test were analyzed. Regarding the energy-based approaches, the input mechanical energy density stored in the material per cycle (i.e., the area of the hysteresis loop), the heat energy dissipated by the material to the surroundings per cycle, and the “2nd-harmonic-based” methods were considered. It was found that for the material analyzed, all the considered energy-based approaches provided a very good engineering estimation of the material fatigue limit compared to a staircase test.

Ultrasonic response to material fatigue

2001 ◽  
Author(s):  
Young-Chul Jung ◽  
Tribikram Kundu
Keyword(s):  
Material Fatigue

Generalization of Spectral Methods for High-Cycle Fatigue Analysis to Accommodate Non-Stationary Random Processes

2019 ◽  
Author(s):  
Mohamed Khalil ◽  
Roland Wüchner ◽  
Kai-Uwe Bletzinger
Keyword(s):  
Sensitivity Analysis ◽  
Fatigue Life ◽  
Spectral Methods ◽  
High Cycle Fatigue ◽  
Random Processes ◽  
Stationary Processes ◽  
Cycle Fatigue ◽  
Material Fatigue ◽  
Frequency Domains ◽  
Stationary Random Processes

Abstract Estimation of material fatigue life is an essential task in many engineering fields. When non-proportional loads are applied, the methodology to estimate fatigue life grows in complexity. Many methods have been proposed to solve this problem both in time and frequency domains. The former tends to give more accurate results, while the latter seems to be more computationally favorable. Until now, the focus of frequency-based methods has been limited to signals assumed to follow a stationary statistic process. This work proposes a generalization to the existing methods to accommodate non-stationary processes as well. A sensitivity analysis is conducted on the influence of the formulation’s hyper-parameters, followed by a numerical investigation on different signals and various materials to assert the robustness of the method.

Wire Bond Failures in Power Modules

2003 ◽  
Author(s):  
S. Ramminger ◽  
G. Wachutka
Keyword(s):  
Failure Modes ◽  
Wire Bonding ◽  
Shear Forces ◽  
Reliable System ◽  
Insulated Gate Bipolar Transistor ◽  
Self Heating ◽  
Material Fatigue ◽  
Igbt Modules ◽  
Power Modules ◽  
Temperature Swing

Power modules are key components for traction applications, railway locomotives, streetcars and elevators, all of which are equipped with Insulated Gate Bipolar Transistor (IGBT) modules. In this application field, a highly reliable system is of uppermost interest. Reliability tests show that wire bonding and soldering may cause the modules to fail. The packaging setup is a multilayer system in which different materials are soldered together. During a temperature swing caused by self-heating and/or by changes in the ambient temperature, the layers expand differently. This generally causes shear forces at the terminations of joint interfaces finally leading to material fatigue and shorter life. In this paper, we give an overview of the wire bonding technique used in power modules and discuss the mechanisms and failure modes associated with it.

Blade Material Fatigue Assessment Using Elman Neural Networks

2007 ◽  
Author(s):  
Jihong Yan ◽  
Pengxiang Wang
Keyword(s):  
Neural Networks ◽  
Testing System ◽  
Steam Turbines ◽  
Material Degradation ◽  
Trend Prediction ◽  
Damage Propagation ◽  
Material Fatigue ◽  
Fatigue Severity ◽  
Propagation Prediction ◽  
The Cost

Material degradation evaluation and life prediction of major components such as blades, rotors, valves of steam turbines not only guarantees reliable, efficient and continuous operation of electric plants, but also offers the promise of substantially reducing the cost of repair and replacement of defective parts, and may even result in saving lives. In this paper, a recurrent neural network based strategy was developed for material degradation assessment and fatigue damage propagation prediction. Two Elman Neural Networks were developed for fatigue severity assessment and trend prediction correspondingly. The performance of the proposed prognostic methodology was evaluated by using blade material fatigue data collected from a material testing system. The prognostic method is found to be a reliable and robust material fatigue predictor.

Influence of Microcalcifications on Stress Development Within a Vulnerable Plaque’s Cap

2011 ◽  
Author(s):  
Ze’ev Aronis ◽  
Erez Kanka ◽  
Eyass Massarwa ◽  
Rami Haj-Ali ◽  
Shmuel Einav
Keyword(s):  
Mechanical Characteristics ◽  
Plaque Rupture ◽  
Intraplaque Hemorrhage ◽  
Rapid Progression ◽  
Stress Concentrations ◽  
Coronary Syndrome ◽  
Vulnerable Plaques ◽  
Material Fatigue ◽  
Mechanical Factors ◽  
As Stress

Vulnerable plaques are inflamed, active, and growing lesions which are prone to complications such as rupture, luminal and mural thrombosis, intraplaque hemorrhage, and rapid progression to stenosis. Despite major advances in the prevention and treatment of this disease, it remains the leading cause of morbidity and mortality worldwide, accounting for 30% of all deaths globally [1]. The importance of stress/strain distribution is now well recognized in vascular pathophysiology, specifically in the mechanisms of plaque rupture. Finite element modeling (FEM) and advanced fluid structure interaction (FSI) studies can better characterize coronary stenosis coupling constitutive equations. Mechanical factors such as stress concentrations within a plaque (material fatigue), lesion characteristic (location, size, and composition), and flow patterns are involved in rupture of plaques. Assessment of local mechanical characteristics caused by plaque structure is important for identifying vulnerable plaques and may improve final estimation of the risk for coronary syndrome.

Sign in / Sign up

Export Citation Format

Share Document