Shear mechanism and bearing capacity calculation on steel reinforced concrete special-shaped columns

J.Y. Xue,Z.P. Chen,H.T. Zhao,L. Gao,Z.Q. Liu 국제구조공학회 2012 Steel and Composite Structures, An International J Vol.13 No.5

An experimental study was performed to investigate the seismic performance of steel reinforced concrete (SRC) special-shaped columns. For this purpose, 17 steel reinforced concrete special-shaped column specimens under low-cyclic reversed load were tested, load process and failure patterns of the specimens with different steel reinforcement were observed. The test results showed that the failure patterns of these columns include shear-diagonal compression failure, shear-bond failure, shear-flexure failure and flexural failure. The failure mechanisms and characteristics of SRC special-shaped columns were also analyzed. For different SRC special-shaped columns, based on the failure characteristics and mechanism observed from the test, formulas for calculating ultimate shear capacity in shear-diagonal compression failure and shear-bond failure under horizontal axis and oblique load were derived. The calculated results were compared with the test results. Both the theoretical analysis and the experimental results showed that, the shear capacity of T, L shaped columns under oblique load are larger than that under horizontal axis load, whereas the shear capacity of ╋-shaped columns under oblique load are less than that under horizontal axis load.

Fuzzy regression method for prediction and control the bead width in the robotic arc-welding process

Xue, Yu,Kim, I.S.,Son, J.S.,Park, C.E.,Kim, H.H.,Sung, B.S.,Kim, I.J.,Kim, H.J.,Kang, B.Y. Elsevier 2005 Journal of materials processing technology Vol.164-165 No.-

<P><B>Abstract</B></P><P>In the manufacturing industry, quality is of prime importance and a reduction in rejects rates is desirable to reduce costs, improve productivity as well as satisfy customer quality requirements. Many quality problems arise due to poorly set process variables, and this is often due to lack of welding skill on the part of the mechanised or robotic system suppliers. However, the automated welding system has not been achieved much because of difficulties of the mathematical model and sensor technologies. In this paper, the possibilities of the fuzzy regression method in modeling the bead width in the robotic arc-welding process are presented. Fuzzy regression is a well-known method to deal with the problems with a high degree of fuzziness so that the approach is employed to build the relationship between four process variables and the quality characteristic, such as bead width. Using the developed model, the proper prediction of the process variables for obtaining the optimal bead width can be determined.</P>

Parametric modeling and shape optimization design of five extended cylindrical reticulated shells

X.Y. Lu,J. WU,S.C. Li,Z.D. Wang,L.P. Li,Y.G. Xue 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.21 No.1

Five extended cylindrical reticulated shells are proposed by changing distribution rule of diagonal rods based on three fundamental types. Modeling programs for fundamental types and extended types of cylindrical reticulated shell are compiled by using the ANSYS Parametric Design Language (APDL). On this basis, conditional formulas are derived when the grid shape of cylindrical reticulated shells is equilateral triangle. Internal force analysis of cylindrical reticulated shells is carried out. The variation and distribution regularities of maximum displacement and stress are studied. A shape optimization program is proposed by adopting the sequence two-stage algorithm (RDQA) in FORTRAN environment based on the characteristics of cylindrical reticulated shells and the ideas of discrete variable optimization design. Shape optimization is achieved by considering the objective function of the minimum total steel consumption, global and locality constraints. The shape optimization for three fundamental types and five extended types is calculated with the span of 30 m~80 m and rise-span ratio of 1/7~1/3. The variations of the total steel consumption along with the span and rise-span ratio are analyzed with contrast to the results of shape optimization. The optimal combination of main design parameters for five extended cylindrical reticulated shells is investigated. The total steel consumption affected by distribution rule of diagonal rods is discussed. The results show that: (1) Parametric modeling method is simple, efficient and practical, which can quickly generate different types of cylindrical reticulated shells. (2) The mechanical properties of five extended cylindrical reticulated shells are better than their fundamental types. (3) The total steel consumption of cylindrical reticulated shells is optimized to be the least when rise-span ratio is 1/6. (4) The extended type of three-way grid cylindrical reticulated shell should be preferentially adopted in practical engineering. (5) The grid shape of reticulated shells should be designed to equilateral triangle as much as possible because of its reasonable stress and the lowest total steel consumption.

Influences of the Irradiation of Intense Pulsed Ion Beam (IPIB) on the Surface of Ni₃Al Base Alloy IC6

X. Y. Le,S. Yan,W. J. Zhao,B. H. Han,Y. G. Wang,J. M. Xue,H. T. Zhang 한국진공학회(ASCT) 2002 Journal of Korean Vacuum Science & Technology Vol.6 No.2

In this paper, we treated the Ni₃Al based alloy samples with intense pulsed ion beams (IPIB) at the beam parameters of 250KV acceleration voltage, 100 - 200 A/㎤ current density and 60 ㎱ pulse duration. We simulated the thermal-mechanical process near the surface of Ni₃Al based alloy with our STEIPIB codes. The surface morphology and the cross-section microstructures of samples were observed with SEM, the composition of the sample surface layer was determined by X-ray Energy Dispersive Spectrometry (XEDS) and the microstructure on the surface was observed by Transmission Electron Microscope (TEM). The results show that heating rate increases with the current density of IPIB and cooling rate reached highest value less than 150 A/㎤. The irradiation of IPIB induced the segregation of Mo and adequate beam parameter can improve anti-oxidation property of IC6 alloy. Some craters come from extraneous debris and liquid droplets, and some maybe due to the melting of the intersection region of interphase. Increasing the pulse number enlarges average size of craters and decreases number density of craters.

A calculation on the Metal - Film Mixing by Intense Pulse Ion Beam (IPIB)

X. Y. Le,S. Yan,W. J. Zhao,Y. G. Wang,J. M. Xue 한국진공학회(ASCT) 2003 Applied Science and Convergence Technology Vol.12 No.S1

In this paper, we studied, by numerical calculation, a system, which was composed of metal-film and metal-substrate irradiated by IPIB with beam ion energy 250 keV, current density 10 to 250 A/㎠. While the IPIB irradiation was going on, an induced effect named mixing occurred. In this case, metal-film and part of metal-substrate melted and mixed. The mixing state was kept as it was in melting phase due to the fast cooling rate. Our works were simulating the heating and cooling process via our STEIPIB program and tried to find proper parameters for a specific filmsubstrate system, 500 ㎚ titanium film coated on aluminum, to get best mixing results. The parameters calculated for such Ti-Al system were compared with the experimental results and were in good accordance to the experimental results.

Soft, skin-mounted microfluidic systems for measuring secretory fluidic pressures generated at the surface of the skin by eccrine sweat glands

Choi, J.,Xue, Y.,Xia, W.,Ray, T.,Reeder, J.,Bandodkar, A.,Kang, D.,Xu, S.,Huang, Y.,Rogers, J. GENERAL AND APPLIED CHEMISTRY JOURNALS 2017 LAB ON A CHIP Vol. No.

A calculation on the Metal-Film Mixing by Intense Pulse Ion Beam (IPIB)

Le, X.Y.,Yan, S.,Zhao, W.J.,Wang, Y.G.,Xue, J.M. The Korean Vacuum Society 2003 Applied Science and Convergence Technology Vol.12 No.1

In this paper, we studied, by numerical calculation, a system, which was composed of metal-film and metal-substrate irradiated by IPIB with beam ion energy 250 keV, current density 10 to 250 A/$\textrm{cm}^2$. While the IPIB irradiation was going on, an induced effect named mixing occurred. In this case, metal-film and part of metal-substrate melted and mixed. The mixing state was kept as it was in melting phase due to the fast cooling rate. Our works were simulating the heating and cooling process via our STEIPIB program and tried to find proper parameters for a specific film-substrate system, 500 nmtitanium film coated on aluminum, to get best mixing results. The parameters calculated for such Ti-Al system were compared with the experimental results and were in good accordance to the experimental results.

MeV Ti ion implantation induced damages in LiNbO₃

S. Yan,W. J. Zhao,H. J. Ma,K. M. Wang,S. L. Li,D. Y. Shen,J. M. Xue,Y. G. Wang 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.-

MeV ion implantation can form a waveguide in LiNbO₃ crystal because of the damage induced by collisions. Damage in LiNbO₃ induced by 0.7-MeV ~ 2.6-MeV Ti ions at doses of 10¹³cm-² and 10 15 cm-² are studied by RBS-C (Channeling Rutherford Backscattering Spectroscopy) analysis and numerical simulation with SRIM (Stopping and Range of Ions in Matter) code. The influence of annealing damage distribution is discussed. The discussion also concerns the topic of the relation between damage distribution and formation of wave-guide. MeV ion implantation can form a waveguide in LiNbO₃ crystal because of the damage induced by collisions. Damage in LiNbO₃ induced by 0.7-MeV ~ 2.6-MeV Ti ions at doses of 10¹³cm-² and 10 15 cm-² are studied by RBS-C (Channeling Rutherford Backscattering Spectroscopy) analysis and numerical simulation with SRIM (Stopping and Range of Ions in Matter) code. The influence of annealing damage distribution is discussed. The discussion also concerns the topic of the relation between damage distribution and formation of wave-guide.

Isostructural metal-insulator transition in VO₂

Lee, D.,Chung, B.,Shi, Y.,Kim, G.-Y.,Campbell, N.,Xue, F.,Song, K.,Choi, S.-Y.,Podkaminer, J. P.,Kim, T. H.,Ryan, P. J.,Kim, J.-W.,Paudel, T. R.,Kang, J.-H.,Spinuzzi, J. W.,Tenne, D. A.,Tsymbal, E. Y. American Association for the Advancement of Scienc 2018 Science Vol.362 No.6418

<P><B>Separating structure and electrons in VO<SUB>2</SUB></B></P><P>Above 341 kelvin—not far from room temperature—bulk vanadium dioxide (VO<SUB>2</SUB>) is a metal. But as soon as the material is cooled below 341 kelvin, VO<SUB>2</SUB> turns into an insulator and, at the same time, changes its crystal structure from rutile to monoclinic. Lee <I>et al.</I> studied the peculiar behavior of a heterostructure consisting of a layer of VO<SUB>2</SUB> placed underneath a layer of the same material that has a bit less oxygen. In the VO<SUB>2</SUB> layer, the structural transition occurred at a higher temperature than the metal-insulator transition. In between those two temperatures, VO<SUB>2</SUB> was a metal with a monoclinic structure—a combination that does not occur in the absence of the adjoining oxygen-poor layer.</P><P><I>Science</I>, this issue p. 1037</P><P>The metal-insulator transition in correlated materials is usually coupled to a symmetry-lowering structural phase transition. This coupling not only complicates the understanding of the basic mechanism of this phenomenon but also limits the speed and endurance of prospective electronic devices. We demonstrate an isostructural, purely electronically driven metal-insulator transition in epitaxial heterostructures of an archetypal correlated material, vanadium dioxide. A combination of thin-film synthesis, structural and electrical characterizations, and theoretical modeling reveals that an interface interaction suppresses the electronic correlations without changing the crystal structure in this otherwise correlated insulator. This interaction stabilizes a nonequilibrium metallic phase and leads to an isostructural metal-insulator transition. This discovery will provide insights into phase transitions of correlated materials and may aid the design of device functionalities.</P>

Effects of loading history on seismic performance of SRC T-shaped column, Part I: Loading along web

J. Wang,Z.Q. Liu,J.Y. Xue,C.M. Hu 국제구조공학회 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.68 No.2

This paper describes an experimental study on the seismic performance of steel reinforced concrete (SRC) T-shaped columns. The lateral loads were applied along the web of the column with different loading histories, such as monotonic loading, mixed loading of variable amplitude cyclic loading and monotonic loading, constant amplitude cyclic loading and variable amplitude cyclic loading. The failure modes, load-displacement curves, characteristic loads and displacements, ductility, strength and stiffness degradations and energy dissipation capacity of the column were analyzed. The effects of loading history on the seismic performance were focused on. The test results show that the specimens behaved differently in the aspects of the failure mode subject to different loading history, although all the failure modes can be summarized as flexural failure. The hysteretic loops of specimens are plump, and minimum values of the failure drift angles and ductility coefficients are 1/24 and 4.64, respectively, which reflect good seismic performance of SRC T-shaped column. With the increasing numbers of loading cycles, the column reveals lower bearing capacity and ductility. The strength and stiffness of the column with variable amplitude cyclic loading degrades more rapidly than that with constant amplitude cyclic loading, and the total cumulative dissipated energy of the former is less.