http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Yield function of the orthotropic material considering the crystallographic texture
Yaroslav A. Erisov,Fedor V. Grechnikov,Sergei V. Surudin 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.58 No.4
On the basis of the energy approach it is reported a development of the yield function and the constitutive equations for the orthotropic material with consideration of the crystal lattice constants and parameters of the crystallographic texture for the general stress state. For practical use in sheet metal forming analysis it is considered different loading scenarios: plane stress and plane strain states. Using the proposed yield function, the influence of single ideal components on the shape of yield surface was analyzed. The six texture components investigated here were cube, Goss, copper, brass, S and rotated cube, as these components are typically observed in rolled sheets from FCC alloys.
Tsung-Han Huang,Cho-Pei Jiang,Fedor V. Grechnikov 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.10
This study investigates the effect of grain size on the deformability of CP2 Titanium to form the mini spur gear in hot squeezing forming process. Experimental specimens are rods with a diameter of 5 mm and annealed with temperature in a range of 500 to 1000°C to precipitate the different initial grain sizes individually. The mechanical properties and hardness of annealed specimens are measured. A mini spur gear die with a modulus of 0.915 and 8 teeth, made of H13 steel, is prepared. The annealed specimens are inserted in die and hot squeezed to form mini spur gear with a temperature of 500°C. The experimental results show that the α-phase microstructure precipitates when the annealing temperature and holding time are 700°C and 3 hours. The specimen with average initial grain size of 154.59 μm results in the maximal elongation and die cavity-filling rate. Harnesses of addendum and dedendum circle are about 215 and 180 MPa that are higher than that of initial grain (107 MPa). The β-phase microstructure precipitates when annealing temperature reaches to 900°C resulting in brittle behavior.
Plane strain bending of a bimetallic sheet at large strains
Sergei E. Alexandrov,Nguyen D. Kien,Dinh V. Manh,Fedor V. Grechnikov 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.58 No.4
This paper deals with the pure bending of incompressible elastic perfectly plastic two-layer sheets under plane strain conditions at large strains. Each layer is classified by its yield stress, shear modulus of elasticity and its initial percentage thickness in relation to the whole sheet. The solution found is semianalytic. In particular, a numerical technique is only necessary to solve transcendental equations. The general solution is cumbersome because different analytic expressions for the radial and circumferential stresses should be adopted in different regions of the whole sheet. In particular, there are several alternative ways a plastic region (or plastic regions) can propagate. However, for any given set of material and process parameters the solution to the problem consists of a sequence of rather simple analytic expressions connected by transcendental equations. The general solution is illustrated by a simple example.