Von Mises Equivalent Stress Research Articles

Effect of Stress Distribution on Transverse and Longitudinal Framing in Cargo Ship using FEA Method

A cargo ship’s hull is made up of bent plates that are not stiffened. The hull can be strengthened by the structural member of the transverse or longitudinal framing system. Frames are strengths member that acts as integral parts of the ship girder when the ship exposed to the longitudinal and transverse stresses. One of the stresses is coming from the load by the container that the cargo ships carry. This research was conducted to analyse how the load does from the container affecting the total deformation and the stress distribution on the transverse framing system model. The analysis of model was using finite element analysis method. Finite element analysis is a numerical technique for solving engineering issues with complex loadings, geometries and material properties. The simulation results of equivalent (von-Mises) stress and total deformation will be compared with the Germanisher Lloyd rule. The result of total deformation and equivalent (von-Mises) stress must not exceed the value stated by Germanischer Lloyd rule. If the value of stress exceeds, it is considered a failure. All the results are not exceed the limit and is acceptable.

Prediction of strength and radial recoil of various stents using FE analysis

The recent developments in engineering and technology over the past few decades have brought many devices that makes human life very comfortable and to cure acute ailments. In current life style, the probability of Coronary Artery Diseases (CAD) is very high even at the younger age throughout the globe. Coronary artery stent implantation is one of the effective and usually used strategies for treatment of coronary heart diseases. The main purpose for stent implantation is to provide mechanical support to the blood vessel wall. Thus, various mechanical properties of different stent materials become important parameters to design and select suitable stent. Inappropriate mechanical properties may cause harm to the vessel wall and in turn human life. This study provides a guideline to understand the mechanical behaviour of various stent materials generally used in terms of selected properties. Deformation behaviour has been studied numerically for various stents using Finite element analysis (FEA) to predict Equivalent Von-Mises Stress, Radial Recoil and Factor of Safety using ANSYS work bench software. Stent of different geometry are modeled using SOLIDWORKS and then structural analysis is performed on Stents of seven different materials viz. SS 316L Stent, Cobalt Chromium L-605 Stent, Bio-Degradable Stent (PCL), Nitinol Stent (Austenite), Elgiloy Stent, Tantalum Stent, Cobalt Chromium MP35 N Stent under normal blood pressure. The ‘Radial recoil’, Equivalent ‘Von-Mises Stress’ and ‘Factor of Safety’ of various stent materials using same stent design and same boundary conditions are compared. The results reveal that the L-605 Cobalt Chromium has low radial recoil and 316 L Stainless Steel is having highest factor of safety among the selected stent materials.

Evaluating the Effect of Wheel Polygons on Dynamic Track Performance in High-Speed Railway Systems Using Co-Simulation Analysis

With increases in train speed and traffic density, problems due to wheel polygons and those caused by wheel–rail impacts will increase accordingly, which will affect train operational safety and passenger ride comfort. This paper investigates the effects of polygonal wheels on the dynamic performance of the track in a high-speed railway system. The wheel–rail interaction forces caused by wheel polygons are determined using a dynamic vehicle–track model, and the results are entered into a slab track finite element model. The influence of the harmonic order and out-of-roundness (OOR) amplitude of wheel polygons on the transient dynamic characteristics of the track(von Mises equivalent stress, displacement, and acceleration) is examined under high-speed conditions. The results indicate that the vibration acceleration and von Mises equivalent stress of the rail increase in proportion to the harmonic order and the OOR amplitude and velocity of a polygonized wheel. The vibration displacement of the rail first increases and then decreases with a change in the harmonic order, and reaches a maximum at the ninth order. The dynamic responses of the concrete slab layer, cement-asphalt layer, and support layer increase linearly with the harmonic order and amplitude of wheel polygons and decrease from top to bottom. Through a combination of numerical simulations and real-time monitoring of rail vibrations, this study provides guidance on potential sensor locations to identify polygonized wheels before they fail.

Finite Element Modeling of Fatigue Life of Steel Wire

In this work, bending fatigue life of steel wire has been studied using finite element modeling by ANSYS program. To verify the finite element results; a fatigue setup was designed and constructed, and the wire was tested using this setup. The results showed that the fatigue life of the wire that bent over the smaller bending diameter has the lower fatigue life, while increasing the bending diameter has a great effect on increasing the fatigue life of steel wire. The finite element results were almost near the experimental results with an accepted percent of deviation. The other values such as, equivalent (Von-Mises) stress, elastic strain, plastic strain, total strain, and the total deformation were estimated using finite element modeling. The Von-Mises parameters results showed that the wire bent over the bigger bending diameter has the lower values in which affect its fatigue life in a positive way.

Stress and Factor of Safety for Connecting Rod using Ansys

The primary link of an IC engine is a connecting rod. Its position is in-between the crankshaft and the piston whose key function is to convert the piston motion which is reciprocating in nature into rotary motion of the crank by transmitting the piston thrust to the crankshaft. This has entailed performing a detailed load analysis. In this paper, connecting rod's finite element analysis was done using Finite Element techniques. So firstly by using the schematic diagram the solid model of the connecting rod was created using Solid works software. Then using the Ansys R17.1 software the meshing was done and then the Finite element analysis is done to find the Equivalent (Von-Mises) stresses and the Factor of Safety under the loading conditions. Structural Steel is the material which is used for connecting rod and the loading conditions are assumed to be static. In Equivalent (Von-Mises) stress test maximum stress is found to be 1.504x108 Pa and the minimum factor of safety is 1.20765 for the connecting rod.

Stress distribution of three-unit fixed partial prostheses (conventional and pontic) supported by three or two implants: 3D finite element analysis of ductile materials

In implantology, when financial or biological feasibility limitations appear, it is necessary to use prostheses with geometries that deviate from the conventional, with a pontic in the absence of an intermediate implant. The aim of this study was analyze and understand the general differences in the stresses generated in implants, components and infrastructures according to the configuration of the prosthesis over three or two implants. Thus, this paper analyzes the von Mises equivalent stresses (VMES) of ductile materials on their external surfaces. The experimental groups: Regular Splinted Conventional Group (RCG), which had conventional infrastructures on 3 regular-length Morse taper implants (4x11 mm); Regular Splinted Pontic Group (RPG), which had infrastructures with intermediate pontics on 2 regular-length Morse taper implants (4x11 mm). The simulations of the groups were created with Ansys Workbench 10.0 software. The results revealed that the RPG presented greater areas of possible fragility due to higher stress concentrations, for example, in the cervical area of the union between the implant and component the top platform of the abutment, as well as greater coverage of the stress by the cervical implant threads. The RPG infrastructure was also more affected by stresses in the connection areas between the prostheses and on the occlusal surface. There is an advantage to using prostheses supported by a greater number of implants (RCG) because this decreases the stress in the analyzed structures and consequently improves stress dissipation to the supporting bone, which would preserve the system.

Stress and Crack Simulation on Axle Housing Mitsubishi L300 Pickup Car using Finite Element Method

Axle housing in pickup cars receives the main load that is direct or indirect. The direct load referred to is the weight of the load and the weight of the vehicle itself, while indirect loading can be in the form of twisting and bending moments. Due to the load experienced by the axle housing will result in deformation, cracking, and even fractured. Based on the case of failure, an analysis of the axle housing was performed which covers two things, namely stress analysis and crack analysis. Axle housing analysis uses the Finite Element Method (FEM) approach, through the Ansys software. The result of stress analysis shows the maximum value of Equivalent (von-mises) Stress is 14,356 MPa, the Maximum Principal Stress is 14,977 Mpa, and the Maximum Shear Stress value is 7,5471 MPa. The result of crack analysis shows the maximum value of J-Integral is 0.00051126 mJ / mm2 and the maximum value of SIFS (K1) is 10.823 MPa.mm0.5.

The Complementary Functions Method Solution to the Functionally Graded Polar Orthotropic Rotating Hyperbolic Disks with Both Radially and Circumferentially Aligned Fibers

In the present study, efforts have been made to numerically evaluate elastic displacements and stresses in a convergent or divergent hyperbolic disk subjected to a centrifugal force of constant circular velocity. The disk material is assumed to be continuously radially functionally graded (FG) with two orthotropic materials based on the simplest Voigt rule with a power of volume fraction of two constituents. The fibers are assumed to be aligned along either radial (RR) or circumferential (CR) directions. Having been a second order differential equation with variable coefficients, the governing equation so-called Navier equation is first derived and then put in the form of two differential equations of first order. These two ordinary differential equation set is originally solved based on the initial value problem (IVP) by employing the Complementary Functions Method (CFM). The numerical results are verified with the corresponding benchmark results for uniform thickness FG polar orthotropic disks. The radial variation of the elastic fields in a hyperbolic disk is investigated for several boundary conditions, disk profile parameters, and the gradient parameter for both the radially and circumferentially aligned fibers. Some numerical results are also presented. Under the case that is considered in this study, it is revealed that the CR disk offers much higher elastic fields than RR disk under all boundary conditions. For a composite rotating disk rotating at a constant speed, it will be better to align fibers along the radial directions, to use convergent disk profiles, and to locate the material having higher radial stiffness at the outer surface. It is also disclosed that the location of the maximum Von-Mises equivalent stress in fixed-free disks varies regarding the fiber orientation.

Design and Analysis of a Divertor Langmuir Probe for ITER

An all-welded ITER divertor Langmuir probe (DLP) model was analyzed by ANSYS 17.0. Temperature field and surface convective heat transfer were obtained by fluid analysis using ANSYS/CFX under both steady-state (10 MW/m2) and slow transient-state (20 MW/m2 for 10 s) working conditions. Mechanical analysis was performed with the temperature field as the preloading condition. The equivalent von-Mises stress and plastic strain distribution have been obtained. The analyzed results show that the DLPs would withstand very high temperature, which can reach 1852°C mainly owing to the extremely high heat flux as well as photon irradiation. The maximum temperature of the copper connection between the DLP and the monoblock would be 792°C, demonstrating that the bonding structure would not be destroyed. All the materials except the alumina pipe have undergone plastic yield analysis, implying that a low cycle strain-fatigue analysis needs to be done in the near future.

The transient response of car body and side windows for high-speed trains passing by each other in a tunnel

The transient responses of car body and side windows for CRH2 high-speed trains passing by each other in a tunnel at different meeting conditions were investigated numerically using the Finite Element (FE) software LS-DYNA/explicit algorithm. Nine meeting cases including the case of meeting at the same speed and at the different speeds were respectively examined, where the moving pressure waves loaded on the surfaces of the observed train were obtained from the previous aerodynamics simulation. The typical transient responses (i.e., the stress and lateral displacement) of car body and side windows were analyzed, and the contribution of pressure wave to structural design strength of car body was also discussed. A comparison between the dynamic pressure wave loading simulation and the equivalent quasi-static loading simulation was also made. The simulation results indicate that both the von-Mises equivalent stress and lateral displacement of the car body are sensitive to the meeting speed. The side windows are subjected to the tensile stress in the most of response stage, and the maximum Y-directional stress of each monitor point presents a rapid increase with the increased meeting speed. The contribution rate of pressure wave to structural strength of the car body increases with the meeting speed. Besides, the dynamic pressure wave loading simulation method is demonstrated to be a better choice to investigate the transient response of the carriage. These research results are significant for ensuring the safety of the trains traveling in tunnels and elevating the safety of side windows.

Finite Element Analysis on Knee Joint with Leg Length Inequality

This study aims to investigate the effect of leg length discrepancy (LLD) on the joint reaction stress and strain of femur particularly in the knee joint. The knee joint model was developed using CATIA and imported into ANSYS to simulate the LLD case based on the value of the joint reaction force from the previous experimental study. The analysis was done under a linear static condition. The knee components were divided on three; bone (femur and tibia), cartilage (femoral cartilage and tibial plateau cartilage) and menisci. The effect of LLD on the knee joint was determined by observing the contour of equivalent stress and strain distribution on the knee joint components and the maximum equivalent von-Mises stress and strain. The result shows a higher value of stress and strain was found on the short leg compared to the long leg due to the LLD. The pattern of overall results shows that the magnitude of stress-strain is proportional to the level of increments in LLD. Since the short leg demonstrate the greater in stress and strain value, it is prone to experience failure in the future such as wear in cartilage.

A computational simulation study on the dynamic response of high-speed wheel–rail system in rolling contact

The dynamic wheel–rail responses during the rolling contact process for high-speed trains were investigated using the explicit finite element code LS-DYNA 971. The influence of train speed on the wheel–rail contact forces (including the vertical, longitudinal, and lateral forces), von Mises equivalent stress, equivalent plastic strain, vertical acceleration of the axle, and the lateral displacement of the initial contact point on the tread, were examined and discussed. Simulation results show that the lateral and longitudinal wheel–rail contact forces are very smaller than the corresponding vertical contact forces, and they seem to be insensitive to train speed. The peak value of dynamic vertical wheel–rail contact force is approximately 2.66 times larger than the average quasi-static value. The elliptical wheel–rail contact patches have multiple stress extreme points due to the plastic deformation of the wheel tread and top surface of the rail. The vertical acceleration value of the axle in the steady condition is around ±5 m/s2 for the perfected wheel–rail system with the running speed below 300 km/h.

Recapitulation of Unilateral Cleft Lip Nasal Deformity on Normal Nasal Structure: A Finite Element Model Analysis.

Cleft lip nasal deformity has been challenging to plastic surgeons. A better understanding of the biomechanical aspect of the cleft nose would contribute to a better correction. In this study, finite element model of a normal nose was constructed and loaded with forces to recapitulate the unilateral cleft lip nasal deformity. Tether at the alar base was simulated by a laterally directed force at the lateral crus, and tether at the columella base by a posteriorly directed force at the medial crus. The equivalent von-Mises stress and the total deformation consequent to different patterns of loading were captured. In accordance with clinical observations, unilaterally loaded forces caused deformation on both sides of the nose. A correlation between the patterns of loading and different cleft lip nasal deformities was documented in detail. When set at the same force magnitude, tether at the columella base led to more extensive changes in the nasal morphology and higher level of stress than at the alar base. Clear identification of major pathological tethers in the nasolabial region might lead to more accurate and stable correction of cleft lip nasal deformities.

Response of a polystyrene foam subjected to large strains and high pressures

This article presents experimental data, and their comprehensive analysis, for a polystyrene foam (with an initial density of 0.623 g/cm3) subjected to large strains and high pressures. The data were obtained from unconfined uniaxial stress tests in compression (at two different strain rates), confined compression tests with compressive strains to almost 50%, and a tension test. The confinement for the compression tests consists of a steel cylinder with external strain gages to monitor the hoop strains due to the radial stresses from the compressed foam. The procedure used to analyze the data allows for a continuous determination of axial, radial and hoop stresses, pressure, and von Mises equivalent stress. A parametric finite element analysis was used to provide for the determination of the stresses from small strains to large strains approaching 50%. There is excellent agreement between test results for similar conditions, as well as the results from data obtained from the confined experiments with two different wall thicknesses. The strength (von Mises equivalent stress) is highly dependent on the pressure, but not as dependent on the strain. The strain rate has a significant effect on strength for the uniaxial stress tests, but only limited data were obtained. Constants were obtained for an existing computational model, and there is good correlation between the experimental data and the model.

Analysis of Fir Tree Root of Aero-engine Disc Assembly for Simultaneous Optimization of Fretting Characteristics

An aero-engine fir tree blade disc assembly is much proven to fretting fatigue damages due to centrifugal and vibrating conditions. This paper examines the effect of disc speed, contact angle and co-efficient of friction on fretting responses such as equivalent von-Mises stress, maximum shear stress and contact pressure by adopting Taguchi based grey relational analysis and RSM. All of the fretting responses were influenced by disc speed and contact angle. Multi response optimization achieved using grey relational analysis indicated that minimum equivalent von-Mises stress (0.63 MPa), shear stress (0.36 MPa) and contact pressure (0.681 MPa) are achieved at 260 rpm of disc speed, 17.5° of contact angle and 0.3 co-efficient of friction. Significant improvement was noticed in terms of stress concentration reduction at optimal conditions. Confirmatory simulation runs were performed to ensure the grey relational analysis results.

Additional Stress on a Buried Pipeline under the Influence of Coal Mining Subsidence

Buried pipelines influenced by coal mining subsidence will deform and generate additional stress during surface deformation. On the basis of the coordinating deformation relationship between buried pipeline and its surrounding soils, a stress analysis method of a buried pipeline induced by mining was proposed. The buried pipeline additional stresses were analyzed; meanwhile, a corresponding analysis process of the pipeline stresses was also presented during mining subsidence. Furthermore, based on the ground subsidence along the pipeline predicted in advance by the probability integral method, the additional stresses and Von Mises equivalent stresses and their distributions along the buried pipeline induced by the exploitation of a coal mining working face named 14101 were obtained. Meanwhile, a comparative analysis of additional stresses between simulation and analytical calculation was performed for the deep analysis and reliability of the results presented by the proposed methodology in this paper. The proposed method provides references for analysis of the additional stress and safety of buried pipelines under the influence of mining subsidence.

Stress distributions in maxillary central incisors restored with different high-stiffness post models: 3-D FEA

Background: Dental root posts are recommended for endodontically treated weakened teeth.Objectives: The present computational FEA study aims to evaluate the effect of material and design of the post on the stress distribution under load in different root canal shapes of endodontically treated maxillary central incisor (MCI).Methods: Three-dimensional models of (MCI) were created by using CAD modeling software and divided into two groups. Group-I comprised five models of a weakened root restored using different post materials (stainless steel, titanium, gold-alloy, Ni-Cr, and zirconium). Group-II: involved four models of (MCI) with two different root canal shapes (small and wide) restored using cylindrical (C-Post) and two-stage tapered (T-Post) posts. Each tooth model was subjected to a 100 N oblique load at the palatal surface of the crown. Von Mises equivalent stresses on dentin and post, as well as shear stresses on the post cement, were evaluated.Results: In Group-I: Ni-Cr produced the lowest stress values on the dentin, where titanium and gold-alloy posts produced the lowest stresses in the post and post/root interfaces. In Group-II: Roots restored with a T-Post showed a lower concentration stress in the dentin and lower shear stresses in the cement layer compared with those restored with a C-Post.Conclusion: The geometry of the post and the corresponding material play an important role in the stress behavior of restored teeth. The use of titanium or gold-alloy T-Posts seems a good way to improve the stress distribution profile and reduce the risk of restoration failure.  Â

Performance analysis of an array of square micro-fins

Array of micro pin fin heat sinks shows higher thermal efficiency in high heat flux and critical devices such as aerospace, microelectronic etc. In this work, an array of micro square pin fins has been designed and for this copper is selected as workpiece material. Moreover, a numerical investigation of thermal performances and mechanical behavior of the designed fins has been carried out. The effects of Reynolds numbers on velocity profile and heat transfer performance have also been studied. Additionally, the equivalent (von-Mises) stress along with the structural and total deformations have been observed at the desired pressure applied on the surface of the pin fins. Numerical simulations with similar parametric conditions have also been conducted on a plate having the same dimensions without fins, and a comparison has been made with a plate having micro-fins. It has been observed that the array of square micro pin fins gives a better thermal performance than that of without fins.

Mechanical analyses of critical surgical maneuvers in the correction of cleft lip nasal deformity.

The relapse of nasal deformity is a challenge for modern correction of cleft lip. A comprehensive understanding in the biomechanical perspective of both the formation and correction of the cleft lip nasal deformity would lead to improved stability of the corrective outcome. In this study, a finite element model of secondary cleft lip nasal deformity was constructed, on which two critical corrective maneuvers were mimicked in the form of force-loading. The intercrural suture was simulated by a force loaded at the intermediate crus of the alar cartilage directing anteriorly and medially, and the suture suspending the alar cartilage to the upper lateral cartilage was simulated by a force loaded at the lateral crus directing superiorly and medially. The equivalent von-mises stress and the total deformation consequent to different patterns of loading were captured. Our biomechanical analyses suggested that the intercrural suture at the nasal tip might be more effective in generating widespread morphological change than the suspension suture, but left much higher level of stress within the skin envelope if placed too high. Synergistic effect was observed between the two sutures in both the resultant deformation and stress. In addition, our simulations were partially supported by clinical photogrammetry data.

Simulation of Excavator Bucket Pressuring Through Finite Element Method

Excavator bucket tool is one of the most important parts of an excavator. It is made of steel mixture. It is commonly equipped with protruding teeth on its cutting side to breakdown hard materials and also to prevent dryness and damage of the bucket. Excavator bucket tooth must have supporting geometrical shape to penetrate and to endure the digging process on the ground, gravels, stones, or any other abrasive field. It is because of the field’s natural characteristic when the bucket tool grinds the material. Mixed iron is common to be used as excavator bucket tool’s material because it is easy to get and economic. High hardness value is also needed on the surface that transports hard material such as mining equipment. Therefore, an accurate analysis should be done to determine the suitable material on this field. Design and analysis were done by using Computer-Aided Engineering (CAE) Abaqus 6.10 application to get the maximum tension as the result of loading. Analysis process to get the tension was done by adding 8285.06 N weight forces in static condition with the angle of 32o to the horizon. From the analysis it could be known that maximum tension experienced by excavator bucket tooth is 209.3 MPa, and it is still below the Maximum Equivalent von Mises stress so the design could be categorized as safe.