Papers by Author: Bin Chen

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Authors: Bin Chen, X. Peng, Xiang Guo Zeng, X. Wu, S. Chen
Abstract: Casting magnesium alloys are heterogeneous materials containing numerous voids. Assuming the voids are spherical, in the present investigation, the evolution equations of the growth and nucleation of the voids have been presented. Combining the evolution equation of the void growth with that of the void nucleation, the evolution rule of the voids was obtained. Based on the void evolution rule a nonclassical elastoplastic constitutive model involving void evolution was developed. The corresponding numerical algorithm and finite element procedure were developed and applied to the analyses of the elastoplastic response and the porosity of casting magnesium alloy. The calculated results show the satisfactory agreement with experiments.
221
Authors: You Xian Peng, Bo Tang, Hong Ying Cao, Bin Chen, Yu Li
Abstract: Audible noise prediction is a hot research area in power transmission engineering in recent years, especially come down to AC transmission lines. The conventional prediction models at present have got some problems such as big errors. In this paper, a prediction model is established based on BP network, in which the input variables are the four factors in the international common expression of power line audible noise and the noise value is the output. Take multiple measured power lines as an example, a train is made by the BP network and then the prediction model is set up in the hidden layer of the network. Using the trained model, the audible noise values are predicted. The final results show that the average absolute error in absolute terms of the values by the audible noise prediction model based on BP neural network is 1.6414 less than that predicted by the GE formula.
1356
Authors: Guo Zheng Quan, Yi Xin Wang, Jie Zhou, Bin Chen
Abstract: he Al-6061-T6 tube’s drawing limit and the drawing process’s elasto-plastic behavior were investigated based on the foundational theories of larger deformation and continuum damage mechanics. A mathematical computation equation about the maximum Cockcroft-Latham damage value was converted to an appropriate discrete expression which is easy for FE code to programme, thus the corresponding finite element numerical algorithm for damage computation was developed. By an approach that physical experiments and numerical simulation provide mutual support for the critical damage value, the crack criterion of Al-6061-T6 was evaluated as 1.34. The crack criterion obtained was introduced as important design considerations of tube drawing process. An 3D graph which reflects maximum damage variation according with the diameters at different tube thickness was achieved, according to which the drawing process’s safe and unsafe areas of Al-6061-T6 tube with diameter 10mm at temperature 20°C and drawing velocity 100mm/s was ploted.
69
Authors: Ying Tong, Guo Zheng Quan, Bin Chen
Abstract: The elasto-plastic behavior and the drawing limit of a kind of magnesium alloy tube were investigated based on the foundational theories of the larger deformation of material and continuum damage constitutive model. The corresponding finite element numerical algorithm was developed based on the constitutive model. The non-mandrel drawing limit graph according to the diameter at different tube thickness of an AZ31B tube with diameter 10mm at 250°C and drawing velocity 100mm/s was achieved, and safe & unsafe area got partitioned. The maximum damage value was evaluated to be 0.324 according to height reduction ratio limit and rigid-plastic FE analysis.
951
Authors: Bin Chen, Da Gang Yin, Quan Yuan, Jing Hong Fan
Abstract: Crab carapace is a kind of biomaterial in nature. It behaves favorable strength, stiffness and fracture toughness, which are closely related to its fine microstructure. The observation of scanning electron microscope (SEM) on the carapace of a Cyclodorippoidea crab shows that the carapace is a kind of natural bioceramic composite consisting of calcite crystal layers and collagen protein matrix. The observation also shows that the calcite crystal layers consist further of long and thin calcite crystal sheets and that all the calcite crystal sheets are arranged in a kind of parallel distribution. The maximum pullout energy of the calcite crystal sheets, which is closely related to the fracture toughness of the carapace, is investigated based on the representative model of the parallel distribution. It shows that the long and thin shape as well as the parallel distribution of the calcite crystal sheets enhance the maximum pullout energy and ensure the high fracture toughness of the carapace.
395
Authors: Kārlis A. Gross, S. Walters, Bin Chen
885
Authors: Bin Chen, Ji Luo, Quan Yuan, Ding Fei Zhang, Guo Zheng Quan
Abstract: The mechanical response and failure of the specimens of magnesium alloy AZ61 with different heating rates (HR) and loading rates (LR) were investigated by a Gleeble-1500 thermal-mechanical material testing system. It was found that heating rate has markedly effect on the strength and plasticity of the specimens. The higher the heating rate is, the lower the strength and the smaller of the plasticity of the specimens will be. There is the relatively small effect of the loading rates on the strength and plasticity of the specimens. The metallographs of the failed specimens were also observed. It shows that there are many microvoids in the specimens near the fracture sections. These microvoids may come from the local thermal and stress inconsistency under high heating rate and loading rates and degrade the strength and plasticity of the specimens.
63
Authors: Bin Chen, X. Peng, S. Sun
Abstract: As a typical biological material, bone possesses high fracture strength and fracture toughness, which are closely related to its exquisite microstructure. SEM observation of a cannon bone shows that the bone is a kind of layered bioceramic composite consisting of hydroxyapatite sheets and collagen matrix. The hydroxyapatite sheets are of long and thin shape, distributing in parallel. The fracture toughness of the bone is analyzed with the representative model of the hydroxyapatite sheets and the concept of maximum pullout energy. It is shown that the lathy shape as well as the parallel distribution of the hydroxyapatite sheets increases the pullout energy and endows the bone with high fracture toughness.
1651
Authors: Bin Chen, Quan Yuan, Ji Luo
Abstract: A scanning electron microscope (SEM) was used for the observation of the microstructures of a chafer cuticle. It showed that the cuticle is a kind of biocomposite consisting of complected chitin-fiber plies and sclerous protein matrix. The observation also showed that there are many holes in the cuticle and the complected fibers continuously reel these holes forming a kind of fiber-complected and reeled microstructure. Based on the SEM observation, a kind of biomimetic composite laminate with complected and reeled structure was fabricated with a special mould and process. The ultimate strength of the obtained biomimetic composite laminate was experimentally investigated and compared with that of the conventional drilling-hole composite laminate. It showed that the ultimate strength of the biomimetic composite laminate is markedly larger than that of the drilling-hole composite laminate.
639
Authors: Bin Chen, Quan Yuan, Ji Luo
Abstract: A scanning electronic microscope (SEM) was used for observing the microstructures of a Cockle shell. It showed that the shell is a kind of natural bioceramic composite consisting of aragonite sheets and organic collagen matrix. The aragonite sheets are further composed of aragonite fibers. The aragonite fibers are of long and thin shape and compose various reinforced microstructures, which include a kind of fiber-intersected reinforced one. The fiber-intersected reinforced microstructure was employed as the design example for the structure of man-made fiber-reinforced composite, a kind of fiber-reinforced composite with the fiber-intersected reinforced structure was biomimetically fabricated. The fracture toughness of the biomimetical composite was tested and compared with that of the conventional composite with fiber-parallel structure. It indicated that the fracture toughness of the biomimetical composite is markedly larger than that of the fiber-parallel composite.
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