scholarly journals Finite element 3D numerical simulation study of car braking systems and brake disc/drum – pad/shoe friction couple materials

2020 ◽  
Vol 180 ◽  
pp. 03003
Author(s):  
George Ipate ◽  
Filip Ilie ◽  
Andreea Catalina Cristescu
Keyword(s):  
Finite Element ◽  
Geometric Model ◽  
Structural Deformation ◽  
Outer Side ◽  
Brake Disc ◽  
Outer Diameter ◽  
Stick Slip ◽  
Inner Diameter ◽  
3D Geometric Model ◽  
The Given

Our study uses the finite element method of modeling and analyzing the functioning of a braking system for a modern vehicle, in terms of stress ditributions, structural deformation, wear and thermal gradient of the brake disc and drum. The 3D geometric model of system brake is designed using Solidworks, and the coupled thermal and structural analysis is performed with the ANSYS Workbench R16 program. The brake was applied when the car was 85.7 km / h (ω = 125 rad · s-1), the duration of braking until the car stopped was t = 5 s. For the given example, the coefficient of average friction during braking, considering the pressure on the pad p = 7.5 MPa, is μ = 0.35. It was discovered that the relative deformations of the plate and disc are larger in the area of the outer diameter than that of the inner diameter. This is also outlined by the fact that the pressure is higher on the outer sides than on the inner sides of the plate, the highest value being in the central axis zone of the outer side. Knowing the thermophysical characteristics of the disc and the plate and the working conditions, it was possible to determine the temperature variation during braking. The results of the numerical research revealed that an increase of the contact pressure and / or the relative speed between the contact surfaces implies an increase of the amplitude of the stick-slip phenomenon.

Shell Body Nose Forming by Rotary Swaging Process

2011 ◽  
Vol 213 ◽  
pp. 221-225 ◽  
Author(s):  
Jeong Hwan Jang ◽  
Byeong Don Joo ◽  
Sung Min Mun ◽  
Young Hoon Moon
Keyword(s):  
Finite Element ◽  
Initial Thickness ◽  
Dimensional Changes ◽  
Rotary Swaging ◽  
Inside Diameter ◽  
Before And After ◽  
Forming Characteristics ◽  
Inner Diameter ◽  
The Given ◽  
Diameter Reduction

Studies on the forming characteristics by a rotary swaging process using the sub-scale specimens have been carried out to obtain a shell body nose of desirable quality. To analyze the changes of the nose thickness and length at the respective reduction of inside diameter, the finite element simulations were carried out. As a result, the desired target dimension is satisfied with the diameter reduction of more than 64 % for the given preform. The thickness of nose area increased up to 56.1 % from initial thickness of 2.62 mm to 4.09 mm after swaging. The values of the hardness before and after swaging were 208 HV and 325 HV, respectively. To analyze the dimensional changes (length and thickness) of nose area with decreasing inside diameter, the rotary swaging test was carried out for two different diameter reductions such as 65 % and 67 %. The lengths of nose area for the diameter reductions are 11.79 mm in 65 % and 12.53 mm in 67 %, respectively. At the diameter reduction of more than 67%, the crack occurs when the localized strain hardening reduces ductility in internal area. Therefore, the nose area should be formed from 64% to 67% reduction in target inner diameter.

The Finite Element Analysis of a Heavy Semi-Trailer Frame Based on ANSYS

2014 ◽  
Vol 644-650 ◽  
pp. 455-458
Author(s):  
Yao Ye ◽  
Yong Hai Wu
Keyword(s):  
Finite Element ◽  
Geometric Model ◽  
Reference Method ◽  
Element Model ◽  
Element Analysis ◽  
Emergency Braking ◽  
The Finite Element Analysis ◽  
New Type ◽  
Stress And Deformation ◽  
3D Geometric Model

Frame has important effects on the performance of the whole of heavy semi-trailer. A heavy semi-trailer frame is analyzed and researched on in the finite-element way in this article. The frame of 3D geometric model is established by using Pro/E. And it was imported into the Hypermesh to establish frame finite element model. Frame are calculated by using ANSYS solver in bending condition, emergency braking conditions and rapid turn conditions of stress and deformation conditions. The computational tools and methods we used provide the new type of frame and development with a reference method to refer to in this paper.

A Water Lubricated Hybrid Thrust Bearing: Measurements and Predictions of Static Load Performance

2016 ◽  
Author(s):  
Luis San Andrés ◽  
Stephen Phillips ◽  
Dara Childs
Keyword(s):  
Flow Rate ◽  
Axial Load ◽  
Static Load ◽  
Outer Side ◽  
Outer Diameter ◽  
Test Rig ◽  
Predictive Tool ◽  
Thrust Bearings ◽  
Supply Pressure ◽  
Inner Diameter

Process fluid lubricated thrust bearings (TBs) in a turbomachine control rotor placement due to axial loads arising from pressure fields on the front shroud and back surface of impellers. To date, prediction of aerodynamic induced thrust loads is still largely empirical. Thus needs persist to design and operate proven thrust bearings and to validate predictions of performance derived from often too restrictive computational tools. This paper describes a test rig for measurement of the load performance of water lubricated hydrostatic/hydrodynamic thrust bearings operating under conditions typical of cryogenic turbo pumps. The test rig comprises of a rigid rotor composed of a thick shaft and two end collars. A pair of flexure-pivot hydrostatic journal bearings (38 mm in diameter) support the rotor and quill shaft connected to a drive motor. The test rig hosts two thrust bearings (8 pockets with inner diameter equal to 41 mm and outer diameter equal to 76 mm); one is a test bearing and the other is a slave bearing, both facing the outer side of the thrust collars on the rotor. The slave TB is affixed rigidly to a bearing support. A load system delivers an axial load to the test TB through a non-rotating shaft floating on two aerostatic radial bearings. The test TB displaces to impose a load on the rotor thrust collar and the slave TB reacts to the applied axial load. The paper presents measurements of the TB operating axial clearance, flow rate and pocket pressure for conditions of increasing static load (max. 3,600 N) and shaft speed to 17.5 krpm (tip speed 69.8 m/s) and for an increasing water supply pressure into the thrust bearings, max. 17.2 bar (250 psig). Predictions from a bulk flow model that accounts for both fluid inertia and turbulence flow effects agree well with recorded bearing flow rates (supply and exiting thru the inner diameter), pocket pressure and ensuing film clearance due to the imposed external load. The measurements and predictions show a film clearance decreasing exponentially as the applied load increases. The bearing flow rate also decreases, and at the highest rotor speed and lowest supply pressure, the bearing is starved of lubricant on its inner diameter side, as predicted. The measured bearing flow rate and pocket pressure aid to the empirical estimation of the orifice discharge coefficient for use in the predictive tool. The test data and validation of a predictive tool give confidence to the integration of fluid film thrust bearings in cryogenic turbo pumps as well as in other more conventional (commercial) machinery. The USAF Upper Stage Engine Technology (USET) program funded the work during the first decade of the 21st century.

Masterpieces of Oriental Art. 16: Late Mauryan or Early Śuṅga Ring-stones

1951 ◽  
Vol 83 (1-2) ◽  
pp. 1-2
Author(s):  
John Irwin
Keyword(s):  
Special Interest ◽  
Outer Side ◽  
Full Description ◽  
Outer Diameter ◽  
Complete Ring ◽  
Female Nude ◽  
Surface Decoration ◽  
Inner Diameter ◽  
Victoria And Albert Museum ◽  
Flowering Tree

A carved ring-stone and fragment of a second similar stone, both probably of the late Mauryan or early Śuṅga period, are among minor antiquities of exceptional interest recently acquired by the Indian Section, Victoria and Albert Museum, from the collection of Colonel D. H. Gordon, D.S.O., O.B.E. Both pieces were bought some years ago by Colonel Gordon from a local dealer in the Taxila area. Their special interest derives not only from fineness of craftsmanship but also from the fact that their use has remained an archæological problem for more than seventy years. A full description follows:—A. Ring-stone: greyish-buff sandstone, highly polished. Carved in low relief, the upper surface having two concentric cableedged bands filled with cross-and-reel motives (slightly pyramidal); the sides of the hole with four standing female nudes alternating with four flowering trees. The base and outer sides are left plain.Outer diameter, 3·37 inches. Inner diameter, 1·06 inches. Depth, 1 inch. Weight, 8¾ ounces.B. Fragment of ring-stone: pinkish-buff sandstone, highly polished. Carved in slightly deeper relief, the upper surface decoration being identical with A. A similar standing female nude appears on the side of the hole, but beside her, instead of a flowering tree, there is an Indian “honeysuckle” motive, partly visible. The base and outer side are left plain.The following measurements are based on a reconstruction of the complete ring. Outer diameter, 3·37 inches. Inner diameter, 0·84 inches. Depth, 0·75 inches.

The Stress Analysis of Drilling Derrick Structure Based on Finite Element Method

2012 ◽  
Vol 251 ◽  
pp. 84-90
Author(s):  
Jiang Ping Wang ◽  
Ze Fu Bao
Keyword(s):  
Finite Element ◽  
Working Conditions ◽  
Theoretical Basis ◽  
Optimization Design ◽  
Geometric Model ◽  
Oil Industry ◽  
Element Analysis ◽  
Oil Drilling ◽  
3D Geometric Model ◽  
Bearing Structure

Oil-drilling derrick is the most important integrant of the equipments in oil industry and is also a giant load bearing structure. In this paper, the 3D geometric model of the derrick is created by commercial finite element analysis (FEA) software ANSYS, and the static stresses under several working conditions are analyzed. The displacement and stress distribution of the derrick acquired can lay the theoretical basis for the optimization design of structural and material choices of the derrick further.

A Water-Lubricated Hybrid Thrust Bearing: Measurements and Predictions of Static Load Performance

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Luis San Andrés ◽  
Stephen Phillips ◽  
Dara Childs
Keyword(s):  
Flow Rate ◽  
Axial Load ◽  
Static Load ◽  
Back Surface ◽  
Outer Side ◽  
Outer Diameter ◽  
Test Rig ◽  
Predictive Tool ◽  
Supply Pressure ◽  
Inner Diameter

Process fluid-lubricated thrust bearings (TBs) in a turbomachine control rotor placement due to axial loads arising from pressure fields on the front shroud and back surface of impellers. To date, prediction of aerodynamic-induced thrust loads is still largely empirical. Thus, needs persist to design and operate proven TBs and to validate predictions of performance derived from often too restrictive computational tools. This paper describes a test rig for measurement of the load performance of water-lubricated hydrostatic/hydrodynamic TBs operating under conditions typical of cryogenic turbo pumps (TPs). The test rig comprises of a rigid rotor composed of a thick shaft and two end collars. A pair of flexure-pivot hydrostatic journal bearings (38 mm in diameter) supports the rotor and quill shaft connected to a drive motor. The test rig hosts two TBs (eight pockets with inner diameter equal to 41 mm and outer diameter equal to 76 mm); one is a test bearing and the other is a slave bearing, both facing the outer side of the thrust collars on the rotor. The slave TB is affixed rigidly to a bearing support. A load system delivers an axial load to the test TB through a nonrotating shaft floating on two aerostatic radial bearings. The test TB displaces to impose a load on the rotor thrust collar, and the slave TB reacts to the applied axial load. The paper presents measurements of the TB operating axial clearance, flow rate, and pocket pressure for conditions of increasing static load (max. 3600 N) and shaft speed to 17.5 krpm (tip speed 69.8 m/s) and for an increasing water supply pressure into the TBs, max. 17.2 bar (250 psig). Predictions from a bulk flow model that accounts for both fluid inertia and turbulence flow effects agree well with recorded bearing flow rates (supply and exiting through the inner diameter), pocket pressure, and ensuing film clearance due to the imposed external load. The measurements and predictions show a film clearance decreasing exponentially as the applied load increases. The bearing flow rate also decreases, and at the highest rotor speed and lowest supply pressure, the bearing is starved of lubricant on its inner diameter side, as predicted. The measured bearing flow rate and pocket pressure aid to the empirical estimation of the orifice discharge coefficient for use in the predictive tool. The test data and validation of a predictive tool give confidence to the integration of fluid film TBs in cryogenic TPs as well as in other more conventional (commercial) machinery. The USAF Upper Stage Engine Technology (USET) program funded the work during the first decade of the 21st century.

Effects of Grain Size and Lubricating Conditions on Micro Forward and Backward Hollow Extrusion of Brass

2013 ◽  
Vol 479-480 ◽  
pp. 8-12 ◽  
Author(s):  
Chao Cheng Chang ◽  
Cheung Hwa Hsu ◽  
Jian Cheng Lai
Keyword(s):  
Grain Size ◽  
Finite Element ◽  
Friction Factor ◽  
Metal Forming ◽  
Material Flow ◽  
Outer Diameter ◽  
Grain Sizes ◽  
Friction Factors ◽  
Dry Conditions ◽  
Inner Diameter

Grain size and lubricating conditions influence material flow behaviours in micro metal forming processes. In this study, the brass (JIS C2700) tubes with 1.1 mm outer diameter and 0.5 mm inner diameter were treated by annealing at 400 °C, 500 °C and 600 °C to obtain various microstructures with the grain sizes of 20 μm, 34 μm and 80 μm, respectively. The treated tubes were machined and grounded to be 0.6 mm length specimens for the experiments of micro forward and backward hollow extrusion. Three lubricating conditions, which were dry, full and punch lubricated conditions, were carried out in the experiments. By comparing the upper cup height and rod length of the extruded specimens with the calibration curves established by finite element simulations, it is possible to estimate the friction factors in the processes. The results show that the dry conditions lead to stronger friction effects and thus larger friction factors. Moreover, the friction factor increased with grain size and stroke for all conditions.

scholarly journals Finite Element Simulations of Dynamic Shear Fracture of Hollow Shear Pins

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Zibo Jin ◽  
Jin Zhou ◽  
Daochun Li
Keyword(s):  
Finite Element ◽  
Failure Mode ◽  
Fracture Process ◽  
Failure Load ◽  
Shear Fracture ◽  
Element Model ◽  
Finite Element Simulations ◽  
Structural Deformation ◽  
Fracture Simulation ◽  
Inner Diameter

The shear pin structure is widely used in aeronautics and astronautics structures to deal with emergency structure separation problems. The shear pin design has a strict restriction on the precise failure load and definite failure mode. Previous research has conducted shear fracture tests and simulations of solid shear pins while there is a lack of detailed research on the shear fracture of hollow shear pins with large diameters. In this research, a 3-dimensional finite element model was built based on the actual shear pin installed on the aircraft engine pylon and the model was validated by the experiment. The influences of the inner diameter of hollow shear pins on the shear fracture process were investigated by conducting finite element simulations. The structural deformation, energy dissipation in the fracture process, and failure load of shear pins were evaluated. It is found that as the inner diameter increases, the failure mode of shear pins changed and would result in difficulties on the structure separation. To solve this problem, a new configuration of hollow shear pin was proposed for the purpose of obtaining both desired failure load and failure mode. The new configuration was verified by the fracture simulation and it is found that the new configuration is effective and can be used to improve the shear fracture performance.

scholarly journals Strength Investigation of an Upholstered Furniture Frame with Side Plates of PB, OSB and PLY by Finite Element Method

2020 ◽  
Vol 71 (3) ◽  
pp. 253-259
Author(s):  
Nelly Staneva ◽  
Yancho Genchev ◽  
Desislava Hristodorova
Keyword(s):  
Finite Element ◽  
3D Model ◽  
Geometric Model ◽  
Failure Criteria ◽  
Rotational Stiffness ◽  
Principal Stresses ◽  
Element Analysis ◽  
Service Load ◽  
Upholstered Furniture ◽  
3D Geometric Model

Comparative analysis of the strength characteristics of one-seat upholstered furniture frame with rails of Pinus Sylvestris L. and side plates of PB, OSB and PLY boards was carried out. 3D geometric model of the upholstered furniture frame was created by Autodesk Inventor Pro®. Linear static analyses were carried out by the method of finite elements (FEM) simulating light-service loading. The orthotropic material characteristics of the used materials were considered in the analyses. Two variants of corner joints in the frame (model A – staples and PVAc; model B - staples, PVAc and strengthening elements under the rail of the seat) were considered. The laboratory established coefficients of rotational stiffness of used staple corner joints in the skeleton were considered in finite element analysis (FEA). As result, the distribution of the maximum and minimum principal stresses in the 3D model of upholstered furniture frame side plates were derived and analysed. The worst failure indexes according to Tsai-Wu failure criteria were calculated at heavy-service load. The study provided database of strength values that can help in the engineering of upholstered furniture frames with side plates of PB, OSB and PLY.

Modeling of Subcritical Crack Growth due to Stress Corrosion Cracking: Transition From Surface Crack to Through-Wall Crack

2011 ◽  
Author(s):  
Do-Jun Shim ◽  
David Rudland ◽  
David Harris
Keyword(s):  
Finite Element ◽  
Crack Growth ◽  
Surface Crack ◽  
Leak Rate ◽  
Outer Diameter ◽  
Element Analysis ◽  
Equivalent Area ◽  
Inner Diameter ◽  
Low Probability ◽  
Crack Transition

Recent work conducted using the Advanced Finite Element Analysis (AFEA) method to simulate the ‘natural’ crack growth of a circumferential PWSCC demonstrated that a subcritical surface crack can transition to a through-wall crack with significant differences between the inner diameter and outer diameter crack lengths. In the current version of the xLPR (Extremely Low Probability of Rupture) code, once the surface crack penetrates the wall thickness, an idealized through-wall crack (which has an equivalent area as the final surface crack) is formed. This type of crack transition was selected since no general stress intensity factor (K) solutions were available for crack shapes that would form during the transitioning stages, i.e., non-idealized or slanted through-wall cracks. However, during the pilot study of the xLPR code, it has been identified that this crack transition method may provide non-conservative results in terms of leak-rate calculations. In this paper, in order to compare the ‘natural’ versus ‘idealized’ crack transition behavior, limited example cases were considered where both crack transitions were simulated using 3D finite element analyses. In addition, leak-rate calculations were performed to study how the two different crack transition methods can affect the leak-rates. The results of the present study demonstrate that the ‘idealized’ transition from surface to through-wall crack can significantly affect the leak-rate calculations.

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