Papers by Keyword: Rigidity

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Authors: Cun Sheng Zhao, Shi Jian Zhu, Lu Wang
Abstract: A pit with dimension 200mm×160mm×21mm is digged in the middle of steel plate using carbon-arc air gouging. The pit was polished and welded using CW66J welding rod. Built-in stress, toughness and rigidity was tested to validate the validity.
Authors: Dragoș Florin Chitariu
Abstract: In the paper a research methodology was developed and used to determine the rigidity in the axial direction.The paper presents a the experimental results regarding the total deformation of narrow modules found in the structure of modular sets. The research conducted showed the different evolution of deformation curves in the case of modular structure composed of modules, with different shape and different sizes, in the case of similar loads
Authors: Dragoş Florin Chitariu
Abstract: In the paper a research methodology was developed and used to determine the rigidity in transversal direction of modular fixture structures. The paper presents experimental results regarding the total deformation of modular structure consisting of ”narrow” modules from modular kits. The research conducted showed the different evolution of deformation curves in the case of modular structure, with different shape and different sizes of modules, in the case of similar loads. The experimental results indicate displacements of the entire modular structure alongside the base plate and, also, tilting. The measured deviations of modules from fixture structure may cause "dimensional"/ position deviations (linear displacement of the measurement base) and deviations of shape and orientation-position (angular displacement of the measurement base) of the workpiece during severe machining conditions.
Authors: Bao Dong Shao, Li Feng Wang, He Ming Cheng, Rui Jie Wang, Jian Yun Li, Zi Liang Li, Li Jun Hou, Jie Hou, Chong Tian, Dong Fang Ding
Abstract: Alloy steel 9SiCr is quenched by a certain proportion of mixture gas of nitrogen and spray water at atmosphere, and the continual cooling curve during quenching is determined, the rigidity of quenched workpiece is measured and the metallographic map is captured. The results show that it can improve the cooling effect of quenching medium on the one hand; on the other hand, it can decrease the deformation and residual stress of workpieces. The results show that the rigidity of quenched workpiece is about 62 (HRC), which is corresponding with the rigidity after oil quenching. Martensite phase transformation occurs at the end of quenching that can be seen from the metallographic map.
Authors: Bai Ru Zhu, Yang Song
Abstract: Many tests were carried out to study flexural failure characteristics, ultimate bearing capacity, and stiffness etc of reinforced concrete beams which are embed in basalt FRP bar. The results show that:(1)Basalt FRP bars greatly enhance load bearing capacity. (2) Beam failure characteristic is interfacial bond failure mode. (3) Reinforced beams’ integrity and stiffness are greatly improved, the beam crack resistance significantly improved.
Authors: Guang Ying Ma, Wang Yao, Jun Gao, Peng Wang, Jia Bin Wang
Abstract: In this paper, the finite element software was used to analyze the rigidity of the pump body and the rotor shaft, in order to provide some useful information for the optimal design of pump. The analysis result shows that the rigidity of the pump body model is adequate, but the rotor shaft displacement is a little large, which should be modified. Nomenclature F Centrifugal force of the impeller [N] m Quality of the impeller [kg] w Rotational speed of the impellor [r/min] r Effective radius of the impeller [m] F1 Force on one bearing block [N] M Bending moment on one bearing block [N*m]
Authors: Qian Li, Gang He, Deng Lin Zhu, Jin Rong Wang, Zhi Bin Leng
Abstract: The rigidity of the sheet-metal shears blade carrier affects the shearing quality greatly. The straightness of the processed sheet-metal will decrease and burrs will increase if the rigidity is too low, which even leads to crack of the blade and decrease of the shearing ability of the sheet-metal shear. The model of the blade carrier in a new guillotine sheet-metal shear in Yawei Machine Tool Co., Ltd was established to study its rigidity. The distortion principle of the blade carrier was deduced using a finite element method. The analysis results are coinciding to the measurement result well. The method proposed in this study provides a guide to the design and intensity alignment of the blade carrier in guillotine sheet-metal shear.
Authors: M.U. Kulikov, M.A. Larionov
Abstract: The technological problems of boring deep apertures are investigated in this report. During the research the basic laws of occurrence of these problems have been revealed. The methodology for solving the basic technological problems arising at deep console boring is also discussed
Authors: M.A. Rahman, Nur Atiqah Md Sadan, Mohammad Minhat, Halim Isa, Abu Bakar Baharudin
Abstract: Dimensional accuracy plays important criteria in producing high quality machined parts. This is a big challenge to manufacturers of precision components to produce good quality parts with minimum manufacturing error. The focus of this paper is to study the influence of the machine tool rigidity and cutting parameters on dimensional accuracy in turning operation. A method was prepared for identifying the factors effecting dimensional accuracy in a turning process. Experimental setup involved computerized numerical control (CNC) lathe machine, with VBMT 160404 carbide insert and mild steel, as cutting tool and workpiece respectively. The statistical analysis was used for analyzing and determining the accuracy of experimental data through Minitab statistical software. The regressions model was developed. The developed regression model could be used to predict the dimensional precision of the parts based on machine tool vibration and machining parameters during turning process. This is the aspect to be seriously considered and be applied in attaining sustainable machine tool development during design and development stage and its usage. This finding provides useful guidelines for manufacturers to produce high quality machined parts at minimum manufacturing cost. It was found that the cutting speed, feed rate, final part length, vibration x and vibration z have significant effects on dimensional accuracy of the machined parts.
Authors: Mitja Schimek, Dirk Herzog, Dietmar Kracht, Heinz Haferkamp
Abstract: Nowadays, high requirements are being placed on producing lighter automobiles with a higher strength. To achieve graded strength properties and to improve the rigidity of high strength thin steel sheets, the side effects of laser joining processes can be used. Local physical and geometrical effects which have previously only been observed as side effects can be purposefully used to increase the rigidity and strength of sheet metal structures. By using a focused laser beam with a diameter of several tenths of a millimetre, bead-on-plate and overlap welding seams have been produced. The energy needed to produce this kind of welding seam can be limited to a small area of the workpiece. In comparison to other procedures, the basic material characteristics are retained after welding, the main reason for this being localized heat input. The continual development of laser beam sources to provide higher output powers has extended their spectrum of use in the field of joining technologies. One aim of the research is to produce local physical and geometrical effects with two different laser systems, on the one hand, with an Nd:YAG laser with a maximum output power of 4 kW, and on the other hand with a Yb:YAG laser with an maximum output power of 3 kW. Bead-on-plate and overlap welding seams were produced to demonstrate that rigidity and strength can be increased in metal sheets. The investigations were carried out on two high strength steels H340LA with two different zinc coatings (D and ZE) and TRIP700. The sheets were tested using tensile tests, 3-point bending tests and fatigue strength tests. During the tests, metallographic analyses were carried out. Seven different specimens were investigated, one without bead-on-plate welding seams, and six with different welding geometries, expect the material H340LAZE which was investigated with three various welding geometries. To analyse the complex stress status, investigations of the residual stress and the fracture were done. Calculations of the seam volume were done to be able to calculate the tensile strength for linear bead-on-plate welding seams and the maximum force for bending overlap welding seams. The tensile and bending tests showed that higher forces were needed before failure occurred, e.g. bending the specimens. Furthermore, the investigations showed that the strength of the specimens with welding seams increased, in comparison to the specimens without welding seams. Another result of the experiments is that there is a dependency between the fatigue strength and the position of the seam relative to the direction of the testing force.
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