Design and Research of Double-Layered Cemented Carbide Novel High-Pressure Die

2021 ◽  
Vol 53 ◽  
pp. 42-52
Author(s):  
Sheng Hua Li ◽  
Jin Liang Li ◽  
Jian Zhang Ge ◽  
Xiang Gao
Keyword(s):  
High Pressure ◽  
Shear Stress ◽  
Tungsten Carbide ◽  
Bearing Capacity ◽  
Maximum Shear Stress ◽  
Circumferential Stress ◽  
Cemented Carbide ◽  
Von Mises Stress ◽  
Support Ring ◽  
Supporting Ring

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.

Investigation on stress distribution and pressure capacity of two-layer split high-pressure die based on finite element analysis

2019 ◽  
Vol 233 (14) ◽  
pp. 5048-5055
Author(s):  
Z Yi ◽  
WZ Fu ◽  
MZ Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Pressure ◽  
Stress State ◽  
Von Mises Stress ◽  
Stress Distributions ◽  
Element Analysis ◽  
Round Cylinder ◽  
Von Mises ◽  
Supporting Ring

In order to obtain a higher pressure capacity for the high-pressure die with a larger sample cavity, two types of two-layer split dies with a round cylinder and a quadrate cylinder were designed based on the conventional belt-type die. Finite element analysis was performed to investigate the stress distributions and pressure capacities of the high-pressure dies using a derived Mohr–Coulomb criterion and the von Mises criterion for the cylinder and supporting rings, respectively. As predicted by the finite element analysis results, in the two-layer split dies with a round cylinder, the stress state of the cylinder can be only slightly improved; and the von Mises stress of the first layer supporting ring can be hardly decreased. However, in the two-layer split dies with a quadrate cylinder and sample cavity, the stress state of the cylinder can be remarkably improved. Simultaneously, the von Mises stress of the supporting rings, especially for the first-layer supporting ring, can be also effectively decreased. The pressure capacities of the two-layer split dies with a round cylinder and a quadrate cylinder are 16.5% and 63.9% higher with respect to the conventional belt-type die.

Contact Stress Analysis of NCD Coating on Cemented Carbide

2010 ◽  
Vol 431-432 ◽  
pp. 98-101
Author(s):  
Jia Jing Yuan ◽  
Wen Zhuang Lu ◽  
Dun Wen Zuo ◽  
Feng Xu
Keyword(s):  
Shear Stress ◽  
Elastic Modulus ◽  
Stress Distribution ◽  
Film Thickness ◽  
Contact Stress ◽  
Maximum Shear Stress ◽  
Shear Stress Distribution ◽  
Cemented Carbide ◽  
Low Elastic Modulus ◽  
Film Layer

The contact stress of cemented carbide with NCD coating in elastic contact was analyzed using ANSYS. Factors such as elastic modulus and thickness of NCD film and elastic modulus of interlayer which affect the shear stress distribution of NCD film on cemented carbide substrate were investigated. The results show that the maximum shear stress point moves towards the interface with the increase of film elastic modulus. Film thickness has a significant effect on shear stress distribution of NCD film. High shear stress develops in the film layer with the increase of film thickness. Interlayer with low elastic modulus will cause shear stress concentration in NCD film.

Poisson Ratio Effects on the Von Mises and Maximum Shear Stresses in Cylindrical Contacts

2005 ◽  
Author(s):  
Itzhak Green
Keyword(s):  
Shear Stress ◽  
Poisson Ratio ◽  
Unit Length ◽  
Maximum Shear Stress ◽  
Critical Force ◽  
Von Mises Stress ◽  
Maximum Pressure ◽  
Shear Stresses ◽  
Wide Range ◽  
Von Mises

This work determines the location of the greatest elastic distress in cylindrical contacts based upon the distortion energy and the maximum shear stress theories. The ratios between the maximum pressure, the von Mises stress, and the maximum shear stress are determined and fitted by empirical formulations for a wide range of Poisson ratios, which represent material compressibility. Some similarities exist between cylindrical and spherical contacts, where for many metallic materials the maximum von Mises or shear stresses emerge beneath the surface. However, if any of the bodies in contact is excessively compressible the maximum von Mises stress appears at the surface. That transitional Poisson ratio is found. The critical force per unit length that causes yielding onset, along with its corresponding interference and half-width contact are derived.

Bending Die Design for a Pre-Formed Sheet Metal with a Golden Finger Feature

2008 ◽  
Vol 594 ◽  
pp. 51-56
Author(s):  
Jinn Jong Sheu ◽  
Sheng Hao Fang
Keyword(s):  
Shear Stress ◽  
Material Flow ◽  
Quality Index ◽  
Design Method ◽  
Maximum Shear Stress ◽  
Die Design ◽  
Von Mises Stress ◽  
Design Parameters ◽  
Profile Design ◽  
Von Mises

In this paper, authors proposed an effective quality index of bending operation and a new punch profile design method to prevent defects. The proposed quality index is presented in terms of distance of fracture location with respect to the topmost plane of blank, the maximum von Mises stress, and the maximum shear stress. The Taguchi method with L18 orthogonal array was adopted to evaluate the effects of design parameters and find out the optimum design of punch profile. A new punch feature called “golden finger” was proposed to control the material flow and move the fracture defects out of the trimming line. The results of this study had demonstrated the optimum die design can be achieved with the proposed golden finger feature to obtain a sound product.

Multidisciplinary Design Optimization of the Composite Cooling Structure for Nickel-based Alloy Turbine Blade

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Xiaoru Qian ◽  
Peigang Yan ◽  
Wanjin Han
Keyword(s):  
Shear Stress ◽  
Flow Field ◽  
Turbine Blade ◽  
Maximum Shear Stress ◽  
Three Dimensional ◽  
Leading Edge ◽  
Suction Side ◽  
Structure Design ◽  
Von Mises Stress ◽  
Von Mises

Abstract A designed method, multidisciplinary coupling computation and multiobjective optimization, has been established for the composite cooling structure of heavy gas turbine blade manufactured with a directionally solidified Ni-based superalloy. The method combines the one-dimensional fluid network gas-thermal coupling computation, three-dimensional flow field coupled with solid stress field, and anisotropic stress calculation based on finite deformation crystal slip. The temperature, flow field, Von-Mises stress and maximum resolved shear stress of the blade before and after optimization were analyzed. The results show that the optimized blade has lower maximum blade temperature, a more uniform temperature distribution, a lower flow resistance of the coolant channel at the leading edge than that of the original blade. The maximum Von-Mises stress of the optimized blade increases by 10.05 % more than the original blade. The maximum shear stress on the suction side and the pressure surface of the optimized blade are improved and slightly deteriorated compared with that of the original blade, respectively. The corresponding relationship of the maximum shear stress distribution with the local temperature gradient reveals further space for the improvement of the composite cooling structure. This paper has a particular guiding significance for the cooling structure design of the turbine blade.

scholarly journals The Mechanism of Interface Dilatancy of Cement Mortar Rockbolts

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Yubao Zhan ◽  
Nan Li ◽  
Hui Wang ◽  
Pengqiang Zheng ◽  
Jun Zhang ◽  
...  
Keyword(s):  
Shear Stress ◽  
Bearing Capacity ◽  
Radial Stress ◽  
Cement Mortar ◽  
Maximum Shear Stress ◽  
Interface Layer ◽  
Sand Content ◽  
Dilatancy Angle ◽  
Grouting Material ◽  
Splitting Failure

In this paper, the mechanism of the interface dilatancy of cement mortar rockbolts is studied based on the phenomenon of splitting failure of samples with a high sand content in the grouting material in laboratory tests. A conceptual model of the interface layer is used to explain the dilatancy mechanism of the interface. Based on the thick-walled cylinder theory, the causes of splitting failure of the samples are analyzed. By using the numerical simulation method, the influences of different dilatancy angles of the interface layer on the interface shear stress and the radial stress are analyzed. The results show that the sand content of the grouting material has a substantial effect on the bearing capacity of the rockbolt. The higher the sand content in the grouting material is, the more obvious the interface dilatancy will be, and the greater the radial stress generated by dilatancy will be, which will produce a higher bearing capacity of the anchorage system. Under the same load, the maximum shear stress of the interface layer increases with increasing dilatancy angle. Similarly, the larger the dilatancy angle of the interface layer is, the greater the radial stress caused by dilatancy will be. Away from the interface layer, the radial stress decays rapidly. The influence range of the radial stress caused by dilatancy is mainly in the interface layer and the rock nearby.

Experimental Study on Performance of Short-Bonding Interface between CFRP and Concrete

2017 ◽  
Vol 753 ◽  
pp. 331-336
Author(s):  
S.W. Liu ◽  
Jia Wei Zhang ◽  
Jian Chang Zhao ◽  
Run Dong Liu ◽  
Kai Li
Keyword(s):  
Shear Stress ◽  
Bearing Capacity ◽  
Fracture Energy ◽  
Failure Modes ◽  
Concrete Strength ◽  
Maximum Shear Stress ◽  
Ultimate Bearing Capacity ◽  
Bonding Interface ◽  
Interface Fracture ◽  
Interface Shear

Based on double shear test, to study the performance of FRP and concrete bonding interface as the FRP sheet bond length is relatively short (hereinafter referred to as short bond). This paper mainly focuses on the research of interface failure modes, ultimate bearing capacity, interface fracture energy, the development and distribution regularity of strain and stress. Therefore, the interface bond slip relationship curve is obtained through differential operation and data regression analysis on FRP strain values which was gained from test. Results show that: (1) under the condition of short-bonding, damage form of FRP and concrete bonding interface is shear failure which caused sudden destruction to the inner of concrete block; (2) The ultimate bearing capacity, interface fracture energy and maximum shear stress increase with the improvement of concrete strength; (3) the interface shear stress - slip curve is obviously featured as nonlinear, composed of rising and falling, basically presents as a parabolic shape.

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 ◽  
...  
Keyword(s):  
High Pressure ◽  
Bearing Capacity ◽  
Maximum Stress ◽  
Strength Analysis ◽  
The Novel ◽  
Superhard Materials ◽  
The Finite Element Method ◽  
Stress States ◽  
Larger Sample ◽  
Supporting Ring

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.

scholarly journals Parametric Study of the Borehole Drilling in Jointed Rock Mass

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yanan Gao ◽  
Yudong Zhang ◽  
Zetian Zhang ◽  
Minghui Li ◽  
Yingfeng Sun ◽  
...  
Keyword(s):  
Shear Stress ◽  
Rock Mass ◽  
Coal Seam ◽  
Coal Mining ◽  
Joint Angle ◽  
Maximum Shear Stress ◽  
Element Model ◽  
Von Mises Stress ◽  
Maximum Displacement ◽  
Von Mises

Gas is associated with coal mining; it commonly exists in the coal seam. It is one of the major dangers during the production because its reaction between the coal masses may induce the gas-coal outburst as well as it being an expositive matter. The gas accident has caused a huge amount of property damage and casualties. Therefore, the primary precaution for coal mining is gas control. At present, drilling and extraction are the main approaches for gas accident prevention. After drilling, the ground pressure will be released; the gas which is in a free state or absorbed in the coal seam will be easy to extract as the migration channel is enhanced. Hence, one of the most concerned problems is the stress redistribution of the coal and rock mass around the borehole. In practical engineering, there are many joints distributed in the coal and rock strata, so it is necessary to investigate the effect of the drilling in the jointed coal and rock mass. In this paper, the boundary element model of the borehole in the jointed coal and rock mass is established to study the influence of joints on the stress and displacement field. The following results can be obtained. The number of joints has a significant effect on the maximum displacement of the coal and rock mass. The maximum displacement increases with the number of the joint. The position of the maximum displacement shifts from the boundary of the borehole to the far field. Meanwhile, it can be found that the displacement may reach a peak value when the joint angle is 30° and if the joint number is less than 4, and the maximum displacement may occur under the joint angle of 45° and if the joints number continuous increases. The von Mises stress has a trend of increasing with the number of joints when the joint angle is less than 30°, while it has a decreasing trend when the joint angle is larger than 30°. The max stress may occur at the joint angle of 15°. The maximum shear stress occurs mostly in the No. 4 joint and the No.7 joint. When the joint angle is 30°, the maximum shear stress occurs in the No. 3 joint and the No. 4 joint. The overlap of the position of the maximum von Mises stress or the maximum displacement with different joint angles or different numbers of joint leads to a reexploration of such positions. The position of the maximum von Mises stress and the maximum displacement o is relatively steady, which locates symmetrically around the borehole. The line between the points that behaves as the maximum von stress is approximately perpendicular to the joint direction.

Sign in / Sign up

Export Citation Format

Share Document