期刊：
Applied Mechanics and Materials,2012年148-149:286-290 ISSN：1660-9336
通讯作者：
Li, L.S.(linshengli_dr@sina.com)
作者机构：
[LI LinSheng; QIU ChangJun; LI Lan] School of Mechanical Engineering, University of South China, Hengyang 421001, China
通讯机构：
[Li, L.S.] S;School of Mechanical Engineering, , Hengyang 421001, China
会议名称：
2011 International Conference on Machanical Engineering,Materials and Energy(2011年机械工程、材料与能源国际会议 ICMEME 2011)
会议时间：
2011-10-19
会议地点：
大连
会议论文集名称：
2011 International Conference on Machanical Engineering,Materials and Energy(2011年机械工程、材料与能源国际会议 ICMEME 2011)论文集
关键词：
Extended finite element method (XFEM);Gaussian integral;Integration scheme
摘要：
A simple integration scheme is presented for numerical integration in the extended finite element method(XFEM). In this scheme, the integral domain of common triangular mesh is converted to that of standard triangular mesh and the integral domain of standard triangular mesh is converted to that of quadrilateral mesh. By this transformation of integral domain, the strength intensity factors for straight crack are worked out. Finally, the accuracy of this method is analyzed by a typical example. It is concluded that the results obtained by new integral scheme are more accurate and simple than common Gaussian integration scheme.
摘要：
Intensity inhomogeneity may cause considerable difficulties in segmentation of CT image. In order to overcome the difficulties caused by intensity inhomogeneity, the region-scalable fitting (RSF) model was put forward. RSF model draws upon intensity information in local regions with a controllable scale. But only using intensity information may lead to slow convergence rate and poor denoise ability. Combining the method of robust statistics, RSF model is improved in this paper. In the improved model, the intensity in RSF model is replaced with local robust statistics which is the weighted combination of inter-quartile range, mean absolute deviation and intensity median in local region. Inter-quartile range and mean absolute deviation in local region are introduced to sharpen object boundaries, and intensity median in local region is introduced to reduce image noise. The contrast experiments between RSF model and the improved model are provided, which demonstrate the fast convergence rate and robustness to noise of the improved model.
摘要：
This paper utilized self-made high-frequency micro-forging machine to treat NiCrBSi alloy cladded by laser, Optical Microscopy(OM) to study geometric characteristic of plastic deformation, OM and SEM to observe influence on surface microstructure and cracking behavior of the laser cladding layer under micro-forging. The results have shown that: Regularly dendrite microstructure, which is peculiar of laser cladding layer, was broken into pieces. Cracking behavior of laser cladding layer improved greatly.
作者机构：
[Qiu, ChangJun; Chang, Xiyang; Zhou, Ju] Univ S China, Sch Mech Engn, Hengyang, Peoples R China.
通讯机构：
[Zhou, Ju] U;Univ S China, Sch Mech Engn, Hengyang, Peoples R China.
会议名称：
2011 International Conference on Mechatronics and Materials Processing(2011年机电一体化与材料加工国际会议 ICMMP)
会议时间：
2011-11-18
会议地点：
广州
会议主办单位：
[Zhou, Ju;Qiu, ChangJun;Chang, Xiyang] Univ S China, Sch Mech Engn, Hengyang, Peoples R China.
会议论文集名称：
2011 International Conference on Mechatronics and Materials Processing(2011年机电一体化与材料加工国际会议 ICMMP)论文集
关键词：
Micro-forging;Laser cladding;Temperature field;Finite element simulation
摘要：
Micro-plastic deformation was produced on the surface of the laser cladding layer by micro-forging, thus cracks were healed in cladding layer; in order to reduce the thermal stress, preheating the substrate was needed to reduce the temperature gap between cladding layer and substrate. In this paper, temperature field by micro-forging on laser cladding Ni60 layer was simulated on software named DEFORM-2D. Compared the width of cracks, the results showed that reasonable and effective preheating temperature could ensure to reduce or eliminate cracks on laser cladding layer.
作者机构：
[Qiu, ChangJun; Zhou, Ju; Cheng, Xiyang] Univ S China, Sch Mech Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Zhou, Ju] U;Univ S China, Sch Mech Engn, Hengyang 421001, Peoples R China.
会议名称：
2011 International Conference on Mechatronics and Materials Processing(2011年机电一体化与材料加工国际会议 ICMMP)
会议时间：
2011-11-18
会议地点：
广州
会议主办单位：
[Zhou, Ju;Qiu, ChangJun;Cheng, Xiyang] Univ S China, Sch Mech Engn, Hengyang 421001, Peoples R China.
会议论文集名称：
2011 International Conference on Mechatronics and Materials Processing(2011年机电一体化与材料加工国际会议 ICMMP)论文集
关键词：
Micro-forging;Laser cladding;Microstructures;Finite element simulation
摘要：
In the whole process of micro-forging regulation laser cladding layer, the microstructure structure of cladding layer would change. In order to establish the microstructure evolution of the whole process, firstly re-crystallization model was set up based on Avrami equation and experimental data, and various material constants were gained with regress; secondly calculation for the model was carried out on DEFORM-2D,then the results were compared with experimental data, which showed that calculation results of this model kept good consistency with experimental data, and proved that the model could be applied in a full size finite element simulation of the micro forging process.
作者机构：
[Qiu, ChangJun; Zhou, Ju; Tang, DeWen] Univ S China, Sch Mech Engn, Hengyang, Peoples R China.
通讯机构：
[Zhou, Ju] U;Univ S China, Sch Mech Engn, Hengyang, Peoples R China.
会议名称：
International Conference on Manufacturing Engineering and Automation
会议时间：
DEC 07-09, 2010
会议地点：
Guangzhou, PEOPLES R CHINA
会议主办单位：
[Zhou, Ju;Qiu, ChangJun;Tang, DeWen] Univ S China, Sch Mech Engn, Hengyang, Peoples R China.
会议论文集名称：
Advanced Materials Research
关键词：
Laser Cladding;Crack;Micro-Forging;Finite Element (FE) Simulation
摘要：
Micro-plastic deformation is produced on the surface of the laser cladding layer by micro-forging, and crack makes a change in cladding layer. In this paper, a finite element model with a simplified panel strain model elastic-plastic of stress and strain relationship and adaptive meshing technique was used to simulate laser cladding layer crack by using DEFORM-2D software. Laser cladding process of cracks by micro-regulation forging is simulated. Comparing to the measurement of crack width, the results show that micro-forging can make the surface of laser cladding layer the residual tensile stress to adjust compressive stress, and the micro-forging can significantly reduce or eliminate the laser cladding layer crack. Reasonable and effective regulation of high-frequency micro-forging can improve the surface quality in micro-cladding layer.
