scholarly journals Strength Analysis of a Novel High-Pressure Die with Double-Layered Split Structure

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 606
Author(s):  
Zhuo Yi ◽  
Wenzhi Fu ◽  
Mingzhe Li ◽  
Liang Zhao ◽  
Liyan Wang ◽  
...  

A novel double-layered split die (DLSD) was designed to have higher pressure-bearing capacity and larger sample cavity volume. In DLSD, the cylinder and first layer supporting ring are split into several blocks. It has a prismatic cylinder and a quasi-prismatic sample cavity. The stress distribution of DLSD was investigated and compared with that of the conventional belt-type die (BTD) and a single-layered split die (SLSD) by the finite element method. The results show that the SLSD can only decrease the stress of the cylinder as there remains significant stress on the first layer supporting ring. However, the novel DLSD can, remarkably, decrease the stress placed on the cylinder and first layer supporting ring simultaneously due to the improvement of the stress states. Additionally, the maximum stress and pressure-bearing capacity of DLSD with different numbers of split blocks were further investigated. It is concluded that the maximum stress of the cylinder increases gradually with an increase in the number of split blocks. Meanwhile, the pressure-bearing capacity decreases accordingly. The experiments show that the pressure-bearing capacities of DLSD with 4 and 8 split blocks are all remarkably higher than that of the BTD. DLSD with 4 split blocks has relatively higher pressure-bearing capacity. This work presents a promising high-pressure die with a double-layered split structure for the synthesis of superhard materials.

2012 ◽  
Vol 538-541 ◽  
pp. 762-767
Author(s):  
Yu Xian ◽  
Yang Guang

Frame of solar sweeper is complexly welded structure with thin steel plate. The finite element method is applied of the frame strength analysis in two working conditions, full-load static and braking state. HyperMesh software is used for analysis of integral and welded frame model. CWELD is created to simulate the welding connection. The numerical results show that maximum stress of integral frame is 60.24MPa, and maximum stress of welded frame is 70.7MPa under full-load static state. The maximum stress different is 14.8% of two working conditions. The frame of solar sweeper satisfy strength requirement under the two working conditions, when the welding connection is considered. And the frame can be optimized by using these results.


Author(s):  
Sheng Hua Li ◽  
Jin Liang Li ◽  
Jian Zhang Ge ◽  
Xiang Gao

To improve the pressure-bearing capacity, a novel high-pressure die with cemented carbide as the first layer of supporting ring was designed. The novel high-pressure die increases the ultimate load-bearing capacity of the high-pressure die by increasing the pretension of the tungsten carbide cylinder. As the volume of the cemented carbide increases, the difficulty of manufacturing increases, therefore, to reduce the manufacturing difficulty of the cemented carbide supporting ring and reduce the shear stress of the supporting ring, the cemented carbide supporting ring is splited. And through reasonable derivation calculations, the calculation formula suitable for the optimal interference amount of the high-pressure die is obtained. The numerical analysis results show that: when a pressure of 6.2 GPa is applied on the inner wall of the tungsten carbide cylinder, high-pressure die mold that uses cemented carbide as the first layer of support ring (hereinafter referred to as double-layered cemented carbide novel high-pressure die) is lower than the ordinary high-pressure die in term of circumferential stress by 93.34%. In terms of von Mises stress by 21.4%, and term of maximum shear stress by 21.37%. The three principal stress images of the two molds are drawn, which proved that the double-layered hard alloy novel high-pressure die can fully exert the performance of the material and can withstand greater pressure.


2012 ◽  
Vol 605-607 ◽  
pp. 622-625
Author(s):  
Shu Yun Wang ◽  
Qing Mei ◽  
Lin Liu ◽  
Yu Qing Zheng

This article discussed the offshore platform deck crane fatigue performance with the finite element method. In Abaqus Fatigue Module, the fatigue strength analysis for the offshore platform deck crane was executed. Based on the fatigue simulation results and the material S-N curve, we made a reliable assessment of the offshore platform deck crane fatigue life. This fatigue analysis procedure can be easily used for optimizing the deck crane structure and reducing the maximum stress amplitude till to meet the engineering design specification.


2018 ◽  
Vol 55 (1) ◽  
pp. 1-4
Author(s):  
Elena Felicia Beznea ◽  
Ionel Chirica ◽  
Adrian Presura ◽  
Ionel Iacob

The paper is treating the strength analysis of the main deck structure of an inland navigation catamaran for 30 passengers. The main deck should have high stiffness and high strength to resist to external loading and endure high stresses from combined bending and torsion loads. Different materials for sandwich structure of the deck have been analysed by using the Finite Element Method in order to determine the solution which accomplish better designing criteria regarding allowable stress and deformations and total weight.


Author(s):  
Jianqiang Yu ◽  
Xiaomin Dong ◽  
Tao Wang ◽  
Zhengmu Zhou ◽  
Yaqin Zhou

This paper presents the damping characteristics of a linear magneto-rheological (MR) damper with dual controllable ducts based on numerical and experimental analysis. The novel MR damper consisting of a dual-rod cylinder system and a MR valve is used to reduce the influences of viscous damping force and improve dynamic range. Driven by the dual-rod cylinder system, MR fluid flows in the MR valve. The pressure drop of the MR valve with dual independent controllable ducts can be controlled by tuning the current of two independent coils. Based on the mathematical model and the finite element method, the damping characteristics of the MR damper is simulated. A prototype is designed and tested on MTS machine to evaluate its damping characteristics. The results show that the working states and damping force of the MR damper can be controlled by the two independent coils.


2020 ◽  
Vol 18 (1) ◽  
pp. 69-76
Author(s):  
Qiang Wang ◽  
Qizhong Tang ◽  
Sen Tian

AbstractMolecular dynamics (MD) analysis of methane hydrate is important for the application of methane hydrate technology. This study investigated the microstructure changes of sI methane hydrate and the laws of stress–strain evolution under the condition of compression and tension by using MD simulation. This study further explored the mechanical property and stability of sI methane hydrate under different stress states. Results showed that tensile and compressive failures produced an obvious size effect under a certain condition. At low temperature and high pressure, most of the clathrate hydrate maintained a stable structure in the tensile fracture process, during which only a small amount of unstable methane broke the structure, thereby, presenting a free-motion state. The methane hydrate cracked when the system reached the maximum stress in the loading process, in which the maximum compressive stress is larger than the tensile stress under the same experimental condition. This study provides a basis for understanding the microscopic stress characteristics of methane hydrate.


2008 ◽  
Vol 07 (01) ◽  
pp. 65-67
Author(s):  
CHANGPING ZOU ◽  
LI DU ◽  
XIANDE HUANG

A new type of six-bar swaying machine was put forward, which is an ingenious combination of plane multi-bar mechanism and high pressure oil cylinder. Preliminary analysis shows that this machine has many advantages, such as the torque produced by its unit weight, its small size, its light deadweight, etc. Thus it can be applied to situations that need swaying mechanism with low rotational speed and great torque. Firstly, the mechanism composition and working principle of the swaying machine were introduced. Secondly, parameterized modeling of the mechanism was carried out by utilizing software ADAMS. Then kinematic analysis and kinetic analysis were completed by using ADAMS. Finally, key dimensions were adjusted according to kinetic analysis. These tasks are believed to be beneficial to the development of the novel transmission.


1989 ◽  
Vol 28 (6) ◽  
pp. 763-765 ◽  
Author(s):  
Peter Neubold ◽  
Beatriz S. P. C. Della Vedova ◽  
Karl Wieghardt ◽  
Bernd Nuber ◽  
Johannes Weiss

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 847 ◽  
Author(s):  
Ryoichi Saito ◽  
Nao-Aki Noda ◽  
Yoshikazu Sano ◽  
Jian Song ◽  
Takeru Minami ◽  
...  

This paper deals with the roller chain commonly used for transmission of mechanical power on many kinds of industrial machinery, including conveyors, cars, motorcycles, bicycles, and so forth. It consists of a series of four components called a pin, a bush, a plate, and a roller, which are driven by a sprocket. To clarify the fatigue damage, in this paper, the finite element method (FEM) is applied to those components under three different types of states, that is, the press-fitting state, the static tensile state, and the sprocket-engaging state. By comparing those states, the stress amplitude and the average stress of each component are calculated and plotted on the fatigue limit diagram. The effect of the plastic zone on the fatigue strength is also discussed. The results show that the fatigue crack initiation may start around the middle inner surface of the bush. As am example, the FEM results show that the fatigue crack of the inner plate may start from a certain point at the hole edge. The results agree with the actual fractured position in roller chains used in industry.


2009 ◽  
Vol 131 (3) ◽  
Author(s):  
R. D. Dixon ◽  
E. H. Perez

The available design formulas for flat heads and blind end closures in the ASME Code, Section VIII, Divisions 1 and 2 are based on bending theory and do not apply to the design of thick flat heads used in the design of high pressure vessels. This paper presents new design formulas for thickness requirements and determination of peak stresses and stress distributions for fatigue and fracture mechanics analyses in thick blind ends. The use of these proposed design formulas provide a more accurate determination of the required thickness and fatigue life of blind ends. The proposed design formulas are given in terms of the yield strength of the material and address the fatigue strength at the location of the maximum stress concentration factor. Introduction of these new formulas in a nonmandatory appendix of Section VIII, Division 3 is recommended after committee approval.


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