http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : S.J. Hosseinipour (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
-
F. Zhalehfar,S.J. Hosseinipour,S. Nourouzi,A.H. Gorji 한국소성가공학회 2011 기타자료 Vol.2011 No.8
In this paper, numerical simulations are carried out to determine the forming limit diagram (FLD) of 5083 aluminum alloy. The aim is to predict the effect of strain path change on the forming limit curve (FLC) of this alloy. For this purpose, out-of-plane formability test method with hemispherical punch was simulated by using commercial finite element software, ABAQUSE 6.9. In the first stage, square blanks were modeled and then some of them were pre-strained uniaxially by tension test and some others were pre-strained biaxially by stretching over the hemispherical punch. In the second stage, the formability test specimens’ models were prepared by trimming the pre-strained blanks with the longitudinal axis parallel and perpendicular to the rolling direction. For trimming, a program was written in MATLAB 7.6 which could determine the new elements and introduce their properties to the FEM model. Ductile fracture criteria were used to predict failure. Furthermore, forming limit stress diagram (FLSD) was determined. The numerical results were compared with the experimental findings. Uniaxial pre-straining increased and shifted the FLC to the left hand side of the diagram for both parallel and perpendicular to the rolling direction. Biaxial pre-straining shifted the FLC to the right hand side of the diagram for both directions, and also decreased the FLC for the specimens parallel to the rolling direction.
-
A. Kolahdooz,S. Nourouzi,M. Bakhshi Jooybari,S. J. Hosseinipour 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.10
The purpose of this work is to discuss the microstructures and mechanical properties of thixoforged helical gearbox caps. The mechanicalproperties of semi-solid components can be improved by controlling the process parameters such as solid fraction of alloy, dietemperature, applied pressure, punch velocity, and heat treatment conditions. In this paper, the effects of forming parameters on the microstructuresand mechanical properties of thixoforged A356 helical gearbox caps with an arbitrary shape are studied. The mechanicalcharacteristics were investigated by changing the applied pressure, die temperature, specimen temperature and holding time. The resultsshowed that by increasing the applied pressure from 100 MPa to 150 MPa, the average grain diameter was decreased about 7% and theshape factor was increased about 11%. Also, by increasing the die temperature, the hardness and forming load were decreased about 13%and 21%, respectively. The results illustrated that by increasing the specimen temperature and holding time, there would be an increase inthe grain size of primary α-Al phase, so the hardness of the specimens is decreased.
-
Investigation of the controlled atmosphere of semisolid metal processing of A356 aluminium alloy
A. Kolahdooz,S. Nourouzi,M. Bakhshi Jooybari,S. J. Hosseinipour 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.10
The cooling slope (CS) method is one of the semi-solid methods in which the molten alloy with a suitable amount of superheat ispoured on a cooling slope to achieve a fine and non-dendritic structure. After pouring, the melt, which becomes semisolid at the end ofthe plate, is subsequently poured into a cylindrical steel mold with different mold temperatures. Also, the process has been done in differentcooling slopes and different cooling lengths. This work, at first discusses the effect of these parameters on the final microstructure ofA356 aluminum alloy and then the effect of the controlled atmosphere is discussed. Also, in this research, the advantages of using thecontrolled atmosphere system are discussed by tests such as XRD, SEM and ultrasonic test. Results indicate that the pouring temperature,mold temperature, cooling slope and cooling length have significant effects on the size and morphology of α-Al phase. Also, the controlledatmosphere could optimize the process as well and increase the mechanical properties of alloy.
-
A Comparison between Three Numerical Criteria for Prediction the Forming Limit Diagram of St14 Steel
M. Moslemi,S.J. Hosseinipour,M.E. Hosseini,A.H. Gorji 한국소성가공학회 2011 기타자료 Vol.2011 No.8
In this paper, the forming limit diagram (FLD) of a low carbon steel St14 (DIN 1623) is investigated experimentally and numerically. The objective of this study is to find a numerical criterion which enables a simple and reliable determination of the FLD. For this purpose, Out-of-plane stretching test method with hemispherical punch was simulated by using commercial finite element software, ABAQUSE 6.9. One-quarter of the geometry was used due to symmetry. The material was modeled as elastoplastic and the anisotropic properties were described by the Hill quadratic yield criterion. The model was assumed to be rate independent. Coulomb friction law was defined for all contact surfaces. The simulation process was performed in two steps. In the first step the blank-holder moves down and deforms the blank into the draw-bead. Then the punch moves up at 20 increments and deforms the specimen to a specified displacement. Three numerical criteria including maximum second thickness strain derivative (CRIT1), equivalent plastic strain increment ratio (CRIT2), and total equivalent plastic strain ratio (CRIT3) were evaluated and the forming limit curve (FLC) were obtained. The predicted FLC were compared with experimental data. Unlike the CRIT2, the CRIT1 and CRIT3 were in good agreements with were experimental data. The CRIT1 criterion predicted the lower bound of the experimental results. While by using the CRIT3 criterion both the lower and upper bounds of the experimental results were predicted.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
