Papers by Keyword: Tube

Abstract: SiC_f/SiC composites are one of the candidates for high temperature structural applications because of their high strength and corrosion resistance under severe conditions and stability under neutron irradiation [1~3]. A silicon carbide fuel cladding for the light water cooled reactors (LWRs) may allow a number of advances, including: the increased safety margins under transients and accident scenarios, such as loss of coolant accident; the improved resource utilization via a higher burn-up beyond the present limit of 62 GWd/MTU; and improved waste management [3~5]. Some components of SiC_f/SiC composite will be applied as tubular geometry for the high-temperature core parts. The proposed design of an advanced LWR fuel cladding, referred to as Triplex, consists of three layers: an inner SiC monolith, a central SiC_f/SiC composite, and an outer dense SiC evrionmental barrier coating. The inner SiC layer provides the strength and hermeticity to contain fission products. The SiC_f/SiC composite layer fabricated by the CVI process provides a pseudo-ductile failure mode. The outer SiC thin coating layer protects against corrosion [5]. The chemical vapor deposition (CVD) technique is an effective approach for the fabrication of SiC_f/SiC composite and coated SiC monolith [6]. To increase the homogeneity of the microstructure and the deposition rate of a SiC tube, the process parameters should be optimized and modified.

Abstract: Working principle and advantages of tube in hydroforming with radical crushing were described and introduced briefly. The research status of deformation behaviors of tube in hydroforming with radical crushing with the tube cross-section shape was made into triangle, rectangle or trapezoid were reviewed in this paper. Finally, the development trend and burning questions of tube in hydroforming with radical crushing were predicted.

Abstract: A theoretical and experimental analysis of heat induction bending for tubes used in the power industry is performed. First, the design of the heat induction bending process for tubes is described and industrial application areas for this technology are presented. Next, the main methods for tube bending with local induction heating are discussed and the effect of the technology on geometrical parameters of bends formed is presented. Then, the heat induction bending process for tubes is modeled using numerical techniques (FEM). The simulations are performed in a three-dimensional strain state, where thermal phenomena are taken into account, using the commercial software package Simufact Forming v. 11.0. In the simulations, the changes in workpiece geometry in the region of the bend being made (cross section ovalization, darkening and thickening of walls, neutral axis position) are examined. Also, potential phenomena that could limit the stability of the bending process and cause shape defects are predicted. The results of the numerical modeling are then compared to those obtained under industrial conditions.

Abstract: The Incremental Profile Forming process (IPF) is a new method to manufacture tubes and profiles with variable cross-section design along the centre-line of the profile. The innovative process design enables the combination of high workpiece complexity and high process flexibility. For this reason, a machine concept was developed and finally a prototype realized. The new machine consists of eight numerically controlled axes, which allow the processing of thinwalled tubes and profiles with a maximum diameter of 80 mm. The design of the machine combined with the control system leads to a forming technology with a high degree of flexibility, which is an advantage of the process. Depending on the final workpiece shape the forming process proceeds in several steps and can therefore be considered as an incremental forming process. Furthermore, the tool concept supports both a kinematical and a form-closed forming process.

Abstract: The tube is a significant machine part in a car.It provides the important contact and fixed functions during the steering of a car. An inaccurate tube size cannot provide steering stability. For example, if the difference in diameter between the front and back of a tube is very large, the car moving at high speeds will be to swing, although steering would still be possible. A car can be made safer at high speeds by controlling the difference between the front and back diameters of the tube. High temperature welding of various parts to the tube, heats the tube almost 2,000°C, so the consequent deformation of the tube must be controlled.

Abstract: Hydroforming has many advantages over other processes, especially when runs are small and shapes are complex. The hydroforming process of automobile front transom was simulated by FEM, which is based on elastic-plastic finite element method and BT shell element theory. The effect of forming process parameters such as internal pressure loading path and initial tube size were simulated and discussed. The simulation results indicated that suitable initial tube size and loading path can observably improve the distribution of the thickness and forming limit of the tube. And for the front transom, tube size Ø55mm and bilinear loading path are the best process parameters.

Abstract: Analysis of inhomogeneous residual stress (RS) fields in bodies is one of the major problems of the mechanics of deformable solid bodies. In the present research the new techniques of identification of inhomogeneous RS in bodies are developed on the basis of surface displacement measurement in a set of points under vibrating sounding load. Corresponding nonlinear ill-posed inverse problems (IP) are formulated and solved numerically by means of iterative regularization. Based on computational experiments, the most advantageous sounding load types and frequency ranges providing the best reconstruction accuracy are revealed. The examples for a cantilever, a plate, a layer, and a cylindrical tube are presented.

Abstract: In nuclear power plants, the steam generator heat transfer tube is the weakest part of the primary circuit pressure boundary. Flow induced vibration is one of the main reasons for the failure of the heat transfer tube. In this paper, an ANSYS finite element software is used to carry out the modal analysis of the heat transfer tube, and to simulate the dynamic response of the heat transfer tube in the harmonic load based on the modal analysis.

Abstract: In most of the existing sealing machine of tube, the sealing efficiency is universally low, this paper apply concentrated forcing scheme to the movable sealing plate, and create a new model of sealing of the tube, using the professional analysis software Inventor to carry out stress analysis for the movable sealing plate, the results show, in concentrated forcing scheme, the movable sealing plate can satisfy the force demand, and the space of the movable sealing plate can be greatly used, multiple tubes can be sealed at the same, the sealing efficiency of tube is greatly improved.

Abstract: In the existing squeezing machine of tube, the squeezing quality of tube is universally unstable, this paper apply dispersed forcing way to the movable squeezing plate, and build a new model of squeezing of the tube, using the professional analysis software Inventor to carry out stress analysis for the movable squeezing plate, the results show, in dispersed forcing way, the structural of model of squeezing of the tube design to be rational, and the tube force even, therefore the high-quality tube product can be obtained with the new model of squeezing of the tube.