Showing papers on "Vibration fatigue published in 2009"
TL;DR: In this paper, a method for determination of multiaxial load segments from original service histories, where the loaded machine part is meaningfully subjected to fatigue damage, is presented, where load segments are directly separated from a service-loading history, which can be of a random character.
212 citations
TL;DR: In this paper, the authors compared the fatigue damage accumulated under uni-axial loading (a procedure promoted by the vibration testing standards) to that induced by multiaxial loading and concluded that simultaneous multi-axis vibration testing can improve significantly the laboratory's vibration simulation realism.
107 citations
TL;DR: In this article, a two-parameter fatigue crack growth model based on the local stress-strain material behaviour at the crack tip was used to account for the variable amplitude loading effects.
87 citations
TL;DR: Vibration fatigue test and analysis methodology for flip chip solder joint fatigue life assessment have been developed by performing vibration tests with constant G -level and varying G-level input excitation to predict vibration fatigue life.
81 citations
TL;DR: In this article, the development and reliability of new Pb-free solders is crucial for the successful substitution of these materials in the electronics industry, and the developments in all these areas are critically examined in this paper.
Abstract: Electronic packaging is a critical part of products such as computers, cellular phones, automotive components and other electronic devices. The package must be tailored to incorporate as many input/output interconnects as possible, in a limited amount of space. Until recently, most solder balls were made of a eutectic Pb–Sn alloy, because of its low melting point, excellent wetting characteristics and adequate creep and thermal fatigue strength. The potential health hazards associated with the toxicity of lead are significant. Given the widespread use of Pb–Sn solder in the manufacture and assembly of circuit boards, the development and reliability of new Pb-free solders is crucial for the successful substitution of these materials in the electronics industry. Pbfree solder alloys are complex materials with various important microstructural attributes. These include the nanoscale precipitates of Ag3Sn in Sn–Ag–Cu or Sn–Ag alloys, as well as Cu6Sn5 intermetallic formed at the interface between the solder and Cu metallisation. The mechanical behaviour of solder alloys is extremely important because solder joints must retain their mechanical integrity under a myriad of conditions such as creep, thermal fatigue, and mechanical shock and drop resistance. A significant amount of work has been carried out on the monotonic shear, creep and thermal fatigue resistance of these materials. An important new area of research is the mechanical shock and vibration fatigue behaviour of Pb-free solders. The developments in all these areas are critically examined in this paper.
81 citations
TL;DR: In this paper, a premature failure that occurs prior to the expected load cycles during the vertical fatigue tests of a rear axle housing prototype is studied, which mainly originated from the same region on test samples.
72 citations
TL;DR: In this paper, a Voronoi finite element method (VFEM) was developed to simulate the microstructure of bearing materials, and the VFEM was then used to investigate the effects of micro-structure randomness on rolling contact fatigue.
Abstract: Microlevel material failure has been recognized as one of the main modes of failure for rolling contact fatigue (RCF) of bearing. Therefore, microlevel features of materials will be of significant importance to RCF investigation. At the microlevel, materials consist of randomly shaped and sized grains, which cannot be properly analyzed using the classical and commercially available finite element method. Hence, in this investigation, a Voronoi finite element method (VFEM) was developed to simulate the microstructure of bearing materials. The VFEM was then used to investigate the effects of microstructure randomness on rolling contact fatigue. Here two different types of randomness are considered: (i) randomness in the microstructure due to random shapes and sizes of the material grains, and (ii) the randomness in the material properties considering a normally (Gaussian) distributed elastic modulus. In this investigation, in order to determine the fatigue life, the model proposed by Raje et al. ("A Numerical Model for Life Scatter in Rolling Element Bearings," ASME J. Tribol., 130, pp. 011011-1-01101}-10), which is based on the Lundberg-Palmgren theory ("Dynamic Capacity of Rolling Bearings," Acta Polytech. Scand., Mech. Eng. Ser., 1(3), pp. 7-53), is used. This model relates fatigue life to a critical stress quantity and its corresponding depth, but instead of explicitly assuming a Weibull distribution of fatigue lives, the life distribution is obtained as an outcome of numerical simulations. We consider the maximum range of orthogonal shear stress and the maximum shear stress as the critical stress quantities. Forty domains are considered to study the effects of microstructure on the fatigue life of bearings. It is observed that the Weibull slope calculated for the obtained fatigue lives is in good agreement with previous experimental studies and analytical results. Introduction of inhomogeneous elastic modulus and initial flaws within the material domain increases the average critical stresses and decreases the Weibull slope.
67 citations
TL;DR: In this article, a computational methodology is proposed for fatigue damage assessment of metallic automotive components and its application is presented with numerical simulations of wheel radial fatigue tests, based on the local strain approach in conjunction with linear elastic FE stress analyses.
61 citations
TL;DR: In this paper, a cycle-dependent model for concrete is proposed to account for the changes of the mechanical properties during the fatigue life, which can be useful in estimating the fatigue-carrying capacity of existing structures that will be subjected to higher loads in the future.
Abstract: Fatigue is a continuous and progressive microcracking mechanism leading to increasing permanent strains and decreasing stiffness in concrete. This paper proposes a time-dependent (i.e, cycle-dependent) model for concrete that accounts for the changes of the mechanical properties during the fatigue life. The proposed method can be useful in estimating the fatigue-carrying capacity of existing structures that will be subjected to higher loads in the future. The model is implemented into a sectional algorithm to reproduce the evolution of the stress-strain state of reinforced concrete members. Redistribution capacity is found to be the main governing factor of the final failure mode. A comparison of theoretical results with existing experimental data of reinforced concrete beams indicates that the model is accurate in the prediction of strain evolution, fatigue life and the mode of fatigue failure.
58 citations
TL;DR: In this paper, a combined high and low cycle fatigue life prediction model for nickel-base single crystal (SC) has been presented to analyze the LCF and high cycle fatigue (HCF) life of SC blade.
54 citations
TL;DR: In this article, an asymptotic interpolation method is proposed to estimate the stress intensity factor (SIF) for cracks at the notch root for both edge notched and center notched components with finite dimension correction.
TL;DR: In this paper, an event independent cumulative damage (EVICD) fatigue prediction model was developed for the fatigue damage prediction under general multiaxial stress state and loading conditions.
TL;DR: In this article, a probabilistic model is presented to predict the formation and propagation of crack networks in thermal fatigue, based on a random distribution of sites where cracks initiate and on the shielding phenomenon corresponding to the relaxed stress field created around cracks.
TL;DR: In this article, the authors studied the risk of fatigue cracks in the rail head and web in the weld zone of a rail and the interaction between the welding residual stress field and the stress field caused by service loads is simulated in a nonlinear finite element (FE) analysis.
01 Jan 2009
TL;DR: In this paper, the authors presented the fatigue life behavior of lower suspension arm using strain-life approach and identified the critical location and selected the suitable materials for the suspension arm, which was selected as a suspension arm materials.
Abstract: This paper presents the fatigue life behaviour of lower suspension arm using strainlife approach. The main objectives of this study are to predict the fatigue life and identify the critical location and to select the suitable materials for the suspension arm. Aluminum alloys are selected as a suspension arm materials. The fatigue life predicted utilizing the finite element based fatigue analysis code. The structural model of the suspension arm was utilizing the Solid works. The finite element model and analysis were performed utilizing the finite element analysis code. In addition, the fatigue life was predicted using the strainlife approach subjected to variable amplitude loading. The three types of variable amplitude are considered in this study. TET10 mesh and maximum principal stress were considered in the linear static stress analysis and the critical location was considered at node (6017). From the fatigue analysis, Smith-Watson-Topper mean stress correction was conservative method when subjected to SAETRN loading, while Coffin-Manson model is applicable when subjected to SAESUS and SAEBRKT loading. From the material optimization, 7075T6 aluminum alloy is suitable material of the suspension arm.
15 Oct 2009-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this paper, a physically based fatigue life calculation method called PHYBAL was developed for constant amplitude and service loading, which combines any kind of load spectra with periodically inserted constant amplitude sequences to measure the plastic strain amplitude, change in temperature and the change in electrical resistance at the same time.
Abstract: In stress-controlled constant amplitude and service loading tests at ambient temperature mechanical stress-strain hysteresis, temperature and electrical resistance measurements were performed to characterize the fatigue behavior of the quenched and tempered steel SAE 4140. The applied measurement methods use deformation-induced changes of the microstructure in the bulk material and represent the actual fatigue state. A new test procedure combines any kind of load spectra with periodically inserted constant amplitude sequences to measure the plastic strain amplitude, the change in temperature and the change in electrical resistance at the same time. The average values of the measuring sequences are plotted as function of the number of cycles in cyclic ‘deformation’ curves and represent the summation of microstructural changes caused by service loading. On the basis of generalized Morrow and Basquin equations the physically based fatigue life calculation method “PHYBAL” was developed for constant amplitude and service loading. With only three fatigue tests, Woehler (S–N) and fatigue life curves can be calculated in very good agreement with experimental ones determined in a conventional manner. The application of “PHYBAL” provides an enormous saving of experimental time and costs.
TL;DR: In this article, two efficient methods for time-dependent fatigue reliability analysis are proposed based on a random process representation of material fatigue properties and a nonlinear damage accumulation rule, which represent different tradeoffs between accuracy and computational efficiency.
Abstract: Two efficient methods for time-dependent fatigue reliability analysis are proposed in this paper based on a random process representation of material fatigue properties and a nonlinear damage accumulation rule. The first method is developed by matching the first two central moments of the accumulated damage to a well-known probability distribution, thus facilitating a direct analytical solution of the time-dependent fatigue reliability. The second method uses the first-order reliability method to calculate the reliability index based on a time-dependent limit state function. These two methods represent different tradeoffs between accuracy and computational efficiency. The proposed methods include the covariance structure of the stochastic damage accumulation process under variable amplitude loading. A wide range of fatigue data available in the literature is used to validate the proposed methods, covering several different types of metallic and composite materials under different variable amplitude loading.
TL;DR: In this paper, a finite element model was developed to predict weld residual stress and simulate the vibratory stress relief Both resonant and non-resonant vibration stress relief were studied to better understand the mechanism of vibration stress relieving.
Abstract: A finite element model was developed to predict weld residual stress and simulate the vibratory stress relief Both resonant and nonresonant vibration stress relief were studied to better understand the mechanism of vibration stress relief The effect of process parameters, vibration amplitude and frequency, of vibration stress relief on weld residual stress reduction was investigated with the developed model It was found that both resonant and nonresonant vibration stress relief can relieve weld residual stresses For the nonresonant vibration, the stress reduction strongly depends on the vibration’s amplitude For the resonant vibration, the vibration’s frequency is essential to stress relief The vibration’s frequency should be close to the structure’s natural frequency for the desired vibration mode
TL;DR: In this paper, a new shape optimization procedure was presented to improve the fatigue life of a V-belt pulley in automotive applications and the shape control concept was introduced to reduce the shape design variables.
TL;DR: In this article, a series of analytical, finite element and experimental analysis were utilized to determine the steady-state stresses and dynamic characteristic of the blade, which is concluded that the blade fracture was due to high cycle fatigue resulting from a bending mode of resonant vibration which probably caused by aero dynamical disturbances.
TL;DR: In this paper, a physically based fatigue life calculation based on comprehensive mechanical, thermal, and electrical fatigue data was developed at the Institute of Materials Science and Engineering at the University of Kaiserslautern.
Abstract: Mechanical stress-strain hysteresis, temperature, and electrical resistance measurements were performed for the microstructurerelated characterisation of the cyclic deformation behaviour and for the fatigue life calculation of metals. The electrical resistance is strongly influenced by the defect density, and allows the detection of a proceeding fatigue damage under cyclic loading and during load-free inspection intervals as well. On the basis of comprehensive mechanical, thermal, and electrical fatigue data the physically based fatigue life calculation “Phybal” was developed at the Institute of Materials Science and Engineering at the University of Kaiserslautern. This method requires only one load increase test and two constant amplitude tests for a fast and nevertheless precise calculation of S-N (Woehler) curves, leading to a significant reduction in experimental time and costs.
TL;DR: In this article, the Modified Wohler Curve Method (MWCM) is used to estimate fatigue lifetime of steel and aluminium welded joints subjected to multiaxial cyclic loading.
01 Oct 2009-Precision Engineering-journal of The International Societies for Precision Engineering and Nanotechnology
TL;DR: In this article, the authors developed a model used to describe the mechanism by which vibration assisted machining reduces tool temperature, and correlations to resulting reduction in tool wear are presented, applied to a newly developed ultrasonic, vibration assisted diamond turning device that allows for variation of vibration frequency and vibration amplitude via a direct drive actuator.
Abstract: The development of a model used to describe the mechanism by which vibration assisted machining reduces tool temperature is discussed, and correlations to resulting reduction in tool wear are presented. This model is applied to a newly developed ultrasonic, vibration assisted diamond turning device that allows for variation of vibration frequency and vibration amplitude via a direct drive actuator. It accommodates a wide range of vibration parameters, including vibration frequencies up to 40 kHz and amplitudes up to 8 μm, where the tool operates. The model uses the finite element method to predict cutting temperatures under conventional turning conditions (i.e., without vibration assistance). The results from the finite element analysis are then used in conjunction with a model developed for vibration assisted machining to predict the new temperature profiles. The modeling techniques and temperature histories for various vibration conditions are presented as well as experimental results that show the thermal advantages of applying tool vibration.
TL;DR: In this paper, a Voronoi finite-element model (VFEM) is used to estimate fatigue lives of microelectromechanical systems (MEMS) devices and account for the effects of topological randomness of material microstructure.
Abstract: This paper presents a fatigue damage model to estimate fatigue lives of microelectromechanical systems (MEMS) devices and account for the effects of topological randomness of material microstructure. For this purpose, the damage mechanics modeling approach is incorporated into a new Voronoi finite-element model (VFEM). The VFEM developed for this investigation is able to consider both intergranular crack initiation (debonding) and propagation stages. The model relates the fatigue life to a damage parameter "D" which is a measure of the gradual material degradation under cyclic loading. The fatigue damage model is then used to investigate the effects of microstructure randomness on the fatigue of MEMS. In this paper, three different types of randomness are considered: (1) randomness in the microstructure due to random shapes and sizes of the material grains; (2) the randomness in the material properties considering a normally (Gaussian) distributed elastic modulus; and (3) the randomness in the material properties considering a normally distributed resistance stress, which is the experimentally determined material property controlling the ability of a material to resist the damage accumulation. Thirty-one numerical models of MEMS specimens are considered under cyclic axial and bending loading conditions. It is observed that the stress-life results obtained are in good agreement with the experimental study. The effects of material inhomogeneity and internal voids are numerically investigated.
TL;DR: In this article, the authors developed a rapid assessment methodology that can determine the solder joint fatigue life of ball grid array (BGA) and chip scale packages (CSP) under vibration loading.
Abstract: Vibration loading has become very important in the reliability assessment of modern electronic systems. The objective of this paper is to develop a rapid assessment methodology that can determine the solder joint fatigue life of ball grid array (BGA) and chip scale packages (CSP) under vibration loading. The current challenge is how to execute the vibration fatigue life analysis rapidly and accurately. The approach in this paper will involve global (entire printed wiring board (PWB)) and local (particular component of interest) modeling approaches. In the global model approach, the vibration response of the PWB will be determined. This global model will give us the response of the PWB at specific component locations of interest. This response is then fed into a local stress analysis for accurate assessment of the critical stresses in the solder joints of interest. The stresses are then fed into a fatigue damage model to predict the life. The goal is to retain as much accuracy and physical insight as possible while retaining computation efficiency.
TL;DR: In this article, the residual stress of web plate by heat treatment due to the manufacturing process and changes of residual stress by braking using finite element analysis is determined by applying finite element method.
TL;DR: In this paper, a fatigue equivalent static load (FESL) methodology for the numerical durability assessment of heavy vehicle structures is presented, where fatigue load requirements are derived from measurements as quasi-static g-loads, the responses to which are considered as stress ranges applied a said number of times during the lifetime of the structure.
TL;DR: The results obtained in the present research put in evidence the decrease of the elastic stiffness during fatigue life before rupture, as well as the stress amplitude during the load cycles plays a role on the lifetime of the test devices.
TL;DR: In this paper, a finite element analysis and fatigue damage parameter determined from fatigue test was used to predict the fatigue life of vulcanized natural rubber components, and the Green-Lagrange strain at the critical location determined from the finite element method was used for evaluating the fatigue damage parameters.
26 May 2009
TL;DR: In this article, the authors discuss lifetime prediction for lead-free soldered flip chips under vibration load in different temperature environments in terms of solder joint fatigue, and the results indicate that temperature is an important parameter affecting the solder joint vibration fatigue life.
Abstract: Electronic assemblies in field use are exposed to a wide range of environmental loads. The interaction of combined loads has to be considered in lifetime estimates of electronic packages. In this paper, we discuss lifetime prediction for lead-free soldered flip chips under vibration load in different temperature environments in terms of solder joint fatigue. Parameters for lifetime modeling are obtained from non-linear and temperature-dependent finite element analysis and lifetime experiments. We introduce temperature dependent coefficients and exponents for the Coffin-Manson-Basquin relationship considering elastic and plastic fatigue behavior. The results indicate that temperature is an important parameter affecting the solder joint vibration fatigue life.