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NEW MULTIOBJECTIVE SIMULATED ANNEALING ALGORITHM AND ITS APPLICATION TO TURBINE CASCADES’ DESIGN

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Chinese Journal of Mechanical Engineering 1999年第1期12卷 51-56页

作者： Tong Tong Feng Zhenping xi’an jiaotong university xi'an jiaotong Univ Xi'an China

A new kind of multiobjective simulated annealing algorithm is proposed,in which the concept of non dominated character is introduced and a new multiobjective acceptance criterion is set *** optimization example of a typical mathematical problem with two minimum objective functions indicates that all of the solutions contract to the set of the non dominated points,and the variation trend of the optimal solutions is verified to be identical with that obtained using Genetic Algor *** new developed algorithm is then applied to the multiobjective optimization design of turbine cascades,in which it is coupled with the aerodynamics computation of the cascade flow fields and performance and the calculated loss coefficient and work potential of the cascade are considered as the objective functions,thus setting up a technique to the engineering optimization design for the *** optimization results,by the view of a group of optimal solutions,show that the algorithm is superior to the traditional technique of multiobjective optimization design and can be applied to more than two objective optimization cascade design problem or other engineering multiobjective optimization designs.

关键词： Simulated annealing algorithm Multiobjective Optimization design Turbine cascade

Analysis of a permeable interface crack in elastic dielectric/piezoelectric bimaterials

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Acta Mechanica Sinica 2007年第6期23卷 681-687页

作者： Qun Li Yiheng Chen School of Aerospace,xi’an jiaotong university,xi’an 710049,China School of Aerospace Xi’an Jiaotong University Xi’an China

A permeable interface crack between elasticdielectric material and piezoelectric material is studied basedon the extended Stroh’s *** by strong engi-neering demands to design new composite materials,theauthors perform numerical analysis of interface crack tip sin-gularities and the crack tip energy release rates for 35 typesof dissimilar bimaterials,respectively,which are constructedby five kinds of elastic dielectric materials:Epoxy,Poly-mer,Al;O;.SiC,and Si;N;and seven kinds of practicalpiezoelectric ceramics:PZT-4,BaTiO;,PZT-5H,PZT-6B,PZT-7A,P-7,and PZT-PIC 151,*** elasticdielectric material with much smaller permittivity than com-mercial piezoelectric ceramics is treated as a special trans-versely isotropic piezoelectric material with extremely *** present investigation shows that thestructure of the singular field near the permeable interfacecrack tip consists of three singularities:r;and r;,which is quite different from that in the impermeable inter-face *** can be concluded that different far field load-ing cases have significant influence on the near-tip fracturebehaviors of the permeable interface *** on thepresent theoretical treatment and numerical analysis,the elec-tric field induced crack growth is well explained,which pro-vides a better understanding of the failure mechanism inducedfrom interface crack growth in elastic dielectric/piezoelectricbimaterials.

关键词： Elastic dielectric Piezoelectric Permeable Interface crack Singularity Energy release rate

DEFORMATION AND MICROFRACTURE OF GRANULAR BAINITE

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Acta Metallurgica Sinica(English Letters) 1992年第6期5卷 432-435页

作者： CHEN Huangpu xi’an jiaotong university,xi’an,China Lecturer,The Research Institute for Strength of Metals,xi’an jiaotong university,xi’an 710049,China xi'an jiaotong Univ Xi'an China

Relationship among deformation history,fracture process and stress distribution of granular bainite has been *** main process of fracture of granular bainite is the forma- *** and coalescence of the *** though the microcracks have formed at the earlier stage of deformation,they are not fateful for fracture because in the successive deformation stage the microcracks change their orientation toward the tensile *** strain hardening rate of granular bainite has a minimal value during the deformation process. Before and after the strain of the minimal value,the material shows different stress distribu- tion and microfracture mechanism.

关键词： granular bainite microfracture strain hardening rate

SIDEBANDS OF X-RAY DIFFRACTION IN AGE-HARDENED Cu-Ti ALLOY

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中国有色金属学会会刊：英文版 1996年第4期6卷 87-93页

作者： Wei Yinghui Wang xiaotian(School of Materials Science and Engineering,xi’an jiaotong university,xi’an 710049) School of Materials Science and Engineering Xi'an Jiaotong University Xi'an 710049 China

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关键词： Cu-Ti alloy X-ray diffraction sidebands static lattice wave theory

CRACK INITIATION POINT DETERMINATION AND DYNAMIC FRACTURE TOUGHNESS FOR CHARPY PRE-CRACKED SPECIMEN

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Acta Metallurgica Sinica(English Letters) 1992年第5期5卷 379-384页

作者： LIN Junshan YAN Wenbin TU Mingjing xi’an jiaotong university,xi’an,China xi'an jiaotong Univ Xi'an China

The method to detect the crack initiation point of Charpy pre-cracked specimen under dy- namie loading was studied using strain *** load-time curve and nominal strain-time curve at the crack tip for impact testing specinens may be shnultaneously measured by twin-channel oscilloscope with high speed sampling and diskette *** on the dynam- ic finite element simulation of impact response of Charpy specimen,the measuring method of dynamic fracture toughness was analysed and some problems in previous dynamic fracture toughness measurement were discussed.

关键词： crack initiation point strain gauge dynamic fracture toughness

FRACTAL ANALYSIS OF FRACTURE SURFACE OF WELDED JOINT UNDER LOW CYCLE FATIGUE

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Acta Metallurgica Sinica(English Letters) 1993年第3期6卷 172-178页

作者： NI Yushan CHENG Guangxu KUANG Zhenbang xi’an jiaotong university,China doctorate student,Institute of Engineering Mechanics,xi’an jiaotong university,xi’an 710049,China xi'an jiaotong Univ Xi'an China

Hausdorff dimension of fracture surface roughness of welded joint,both welding metal and heat-affected *** pressure vessel steel 16MnR,tested under strain-controlled low-cycle fatigue,was examined with computer vision srstem and by two-dimensional variation method. Results show that it decreases with the increase of cyclic hysteresis *** Hausdorff di- mension variation at heat-affected zone is greater than that of weld *** is believed that the greater the fractal dimension is,the longer the fatigue life will be.

关键词： welded joint low-cycle fatigue fractograph Hausdorff dimension

CRACKING BEHAVIOR AND MECHANICAL ANALYSIS ON DUPLEX STRUCTURE UNDER CYCLIC LOADING

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Acta Metallurgica Sinica(English Letters) 1992年第2期5卷 107-111页

作者： WANG Zhaoxia CHAI Donglang LIU Jinghua xi′an jiaotong university,xi′an,China xi'an jiaotong Univ Xi'an China

On the basis of stress-strain analysis under cyclic loading,the mechanism,origin and cyclic number of microcraek nucleation of duplex structure materials,saying ferrite plus martensite, have been experimentally studied and *** results are in fair mutual agreement. The morphology,distribution,size and relative quantities of the constitutional phase,especial ly strengthening phase,as well as the stress-strain distribution and variation in micro-region are directly influential in the origin of microcracks in duplex structure materials.

关键词： stress-strain analysis crack fatigue

RESIDUAL STRESS CONCENTRATION AND ITS EFFECTS ON FATIGUE LIMIT AND SHORT CRACK GROWTH

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Acta Metallurgica Sinica(English Letters) 1993年第2期6卷 96-100页

作者： HE Jiawen HU Naisai ZHANG Dingquan xi’an jiaotong university,xi’an,China Professor,Research Institute for Strength of Metals,xi’an jiaotong university,xi’an 710049,China xi'an jiaotong Univ Xi'an China

Residual stress concentration at a notch depends on both notch geometry and yield strength of the *** varies through the depth,and its magnitude may be higher than the theoretical *** *** concentration at the notch of shot-peened specimen of soft material is easily to he relaxed,with the surface damage during shot-peening results in a mi- nor contribution to the fatigue *** residual stress increases the crack closure effect at the notch and may lead to a non-propagating crack.

关键词： residual stress stress concentration fatigue

ExiSTENCE AND UNIQUENESS OF STRONG PERIODIC SOLUTION OF THE EVOLUTION SYSTEM DESCRIBING GEOPHYSICAL FLOW-PART I: IN BOUNDED DOMAINS

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Chinese Annals of Mathematics,Series B 2001年第3期22卷 385-396页

作者： ZHAO CHUNSHAN, LI KAITAI School of Science, xi’an jiaotong university, xi’an 710049, China. School of Science Xi'an Jiaotang University Xi'an 710049 China

The existence and uniqueness of a strong periodic solution of the evolution system describing geophysical flow in bounded domains of RN (N = 3, 4) are proven if external forces are periodic in time and sufficiently sm... 详细信息

关键词： Existence and uniqueness Periodic solution Evolution system Geophysical flow