Yoshiyuki Furuya

The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 1-2, 2011, DOI:10.3970/icces.2011.016.001

Abstract Gigacycle fatigue takes place in high-strength steel. In this case, fish-eye fracture eliminates a conventional fatigue limit. This means that the fish-eye fracture is a key to understand the gigacycle fatigue of high-strength steel. Evaluation of gigacycle fatigue properties needs accelerated fatigue testing since gigacycle fatigue tests take long time. For example, a 10⁹-cycles fatigue test takes more than 3 months at conventional 100 Hz. For this acceleration, ultrasonic fatigue testing is a very powerful tool since it achieves 20 kHz and completes the 10⁹-cycles in a day. However, frequency effects must sufficiently be investigated before using the ultrasonic fatigue… More >

Ying Wang*, Zhen Wang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.4, pp. 176-176, 2019, DOI:10.32604/icces.2019.05665

Abstract Due to stress concentration as well as welding residual stress, fracture due to vehicle fatigue loads is easy to occur in the weld and its adjacent position of long-span bridge, especially at the toe of weld between the U-rib and orthotropic steel bridge deck. In order to investigate the fatigue crack propagation mechanism of the toe of weld in long-span bridge, a multi-scale finite element model including the whole bridge, local components, the welding details and cracks was established firstly. And then, based on birth and death element technology, the welding heat and structural coupling process simulation was carried out… More >

Akiyuki Takahashi^1,*, Takaki Fujiwara¹, Yuichi Shintaku²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.4, pp. 170-170, 2019, DOI:10.32604/icces.2019.05151

Abstract This paper presents a Paris law-based cohesive zone model (CZM) for fatigue crack growth simulations to enable the consideration of the plasticity induced crack closure effect, which is known to be a source of substantial crack growth retardation. In order to avoid the addition of any redundant model parameters, the basic equation of the CZM is derived from the Paris law so that the CZM has only the parameters of Paris law. Thus, the parameters can be determined by referring the existing experimental data of the Paris law without any troublesome fitting processes. Only the parameter to be fitted is… More >

Hideaki NISHIKAWA*, Yoshiyuki FURUYA

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 126-126, 2019, DOI:10.32604/icces.2019.05354

Abstract Fatigue life is determined by microscopic fatigue crack initiation and growth. Since fatigue crack is generally initiated on the slip plane of microstructure and propagated by slip deformation of the crack tip, fatigue life should depends on microstructure. To computationally simulate the effect of microstructure on fatigue property, it is necessary to understand microstructural small fatigue crack initiation and growth behavior. Although Ti-6Al-4V alloy has superior fatigue strength, fatigue strength of forged pancake, used for such as airplane engine, is normally lower than that of rolled alloy. It is possibly comes from microstructural difference, such as micro-texture. However, it is… More >

Fabien Briffod*, Alexandre Bleuset, Takayuki Shiraiwa, Manabu Enoki

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 125-125, 2019, DOI:10.32604/icces.2019.05319

Abstract The fatigue behavior of metallic materials is a multi-scale problem (from a time and length-scale perspective) intimately influenced by microstructural features that determine the early stages of crack propagation. Prediction of fatigue life is traditionally based on the evaluation of macroscopic mechanical fields at the structure level and on the application of empirical rules. However, these structure-oriented methods are material-specific and do not consider the material variability at lower scales. Hence, reliable prediction of fatigue performances and its variability requires on one side the characterization and quantification of early damage mechanisms and on the other side the incorporation of local… More >

Takayuki Shiraiwa*, Fabien Briffod, Manabu Enoki

The International Conference on Computational & Experimental Engineering and Sciences, Vol.22, No.2, pp. 124-124, 2019, DOI:10.32604/icces.2019.05311

Abstract The purpose of this study is to evaluate fatigue performances of welded structures using numerical simulations. The fatigue life of welded joint is complicatedly affected by various factors such as geometries, defects, residual stress and microstructure. Conventional fatigue life assessments are generally based on fracture mechanics and predict the fatigue life for long crack propagation. In order to predict the total fatigue life more accurately, it is necessary to consider the lifetime for crack initiation and microstructually short crack (MSC) growth. In this study, a numerical framework to predict the fatigue life including crack initiation, MSC growth and long crack… More >

Shunhua Chen^1,*, Shinobu Yoshimura¹, Kaworu Yodo², Naoto Mitsume¹, Yasunori Yusa³, Tomonori Yamada¹, Chisachi Kato⁴, Shori Orimo⁴, Yoshinobu Yamade⁵, Akiyoshi Iida⁶

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.3, pp. 60-60, 2019, DOI:10.32604/icces.2019.05361

Abstract With the pressing requirement of wind energy capacity, the wind turbine blade size has been getting larger and larger in recent decades. For such a large-size blade, it is of prime importance to accurately evaluate the mechanical response under various wind loading conditions. In this work, we present a computational framework to achieve this end. Firstly, a finite element model for a 5MW blade is established according to the well-known NREL report. A composite laminated element is adopted to describe the blade structure. The effectiveness of this model is validated by means of eigenfrequency analysis. Secondly, a one-way partitioned FSI… More >

M. Kikuchi¹, Y. Wada², A. Utsunomiya³, Y. Li⁴

The International Conference on Computational & Experimental Engineering and Sciences, Vol.8, No.2, pp. 67-72, 2008, DOI:10.3970/icces.2008.008.067

Abstract Fatigue crack growth under mixed mode loading conditions is simulated using S-FEM. By using S-FEM technique, only local mesh should be re-meshed and it becomes easy to simulate crack growth. By combining with auto-meshing technique, local mesh is re-meshed automatically, and curved crack path is modeled easily. Three dimensional surface crack problem is solved by this technique. Pure mode I crack and slant crack problems are solved, and fatigue crack growth processes are simulated. The change of aspect ratio of surface crack and distributions of stress intensity factor along crack front are evaluated and discussed. More >

Mijia Yang¹, Qiao Pizhong²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.6, No.3, pp. 157-168, 2008, DOI:10.3970/icces.2008.006.157

Abstract A new fatigue model suitable for polymer matrix composites is proposed, based on dimensional analysis of testing and material variables involved in a fatigue test. The new model has a good physical and theoretical foundation based on progressive damage, and unifies all the material and testing parameters into one general equation. Especially, the model can be simplified to the Goodman relation or Gerber relation when capturing the effect of mean stresses. The model suggested can be used to substitute the classical S-N curves and reduce the testing number by 50{\%} required by ASTM standards. A series of experiments have also… More >

T. Aizawa¹, H. Akebono², H.Suzuki¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.5, No.4, pp. 193-198, 2008, DOI:10.3970/icces.2008.005.193

Abstract In order to achieve power transmission parts like a compact gearwheel which indicates high performance properties, hybrid surface modification was performed by combining Super Rapid Induction Heating & Quenching(SRIQ) which creates high fatigue strength and Diamond Like Carbon (DLC) coating which are well known for their high hardness, low friction and excellent wear resistance. And, in order to prevent the base material from decreasing its fatigue strength, DLC was coated by using Unbalanced Magnetron Sputtering (UBMS) method which can coat at low temperature. Rotational bending fatigue tests and friction-wear tests were carried out. It was clear that it is possible… More >