Damping Variation Effects in Vehicle Semi-active MR Suspensions: A Stress Concentration Analysis

2021 ◽  
Vol 8 ◽  
Author(s):  
Carlos A. Vivas-Lopez ◽  
Juan C. Tudon-Martinez ◽  
Alfonso Estrada-Vela ◽  
Jorge de Jesus Lozoya-Santos ◽  
Ruben Morales-Menendez
Keyword(s):  
Stress Concentration ◽  
Mr Damper ◽  
High Amplitude ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Vehicle Suspensions ◽  
Mechanical Components ◽  
Automotive Suspension ◽  
Suspension Model ◽  
Multi Body

Semi-active vehicle suspensions are used to improve the limited comfort performance of passive vehicle suspensions by varying the damping coefficient according to a control strategy. These benefits have been usually studied in a transient and frequency domain, but rarely in a multi-body dynamic analysis considering the mechanical components and their joints. In this study, the controllability effects of a magnetorheological (MR) damper on the mechanical components of a McPherson automotive suspension are investigated using a stress concentration analysis. Finite element analysis was used with a Quarter of Vehicle (QoV) suspension model configured with an MR damper, and then compared with the passive damper. The simulation results show that an SA damper in the suspension not only improves the dynamic behavior of a road vehicle, but it also has the positive effect of reducing the stress concentrations in a critical suspension element, the knuckle, that are generated by high amplitude road profiles such as rough roads or dangerous street bumps.

Finite element analysis of elastomer used in automotive suspension systems

2019 ◽  
Vol 52 (6) ◽  
pp. 521-536
Author(s):  
R Karthikeyan ◽  
S Rajkumar ◽  
R Joseph Bensingh ◽  
M Abdul Kader ◽  
Sanjay K Nayak
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Uniaxial Stress ◽  
Leaf Spring ◽  
Loading Conditions ◽  
Element Analysis ◽  
Rubber Material ◽  
Hyperelastic Materials ◽  
Automotive Suspension

Present research endeavours towards the development of a methodology to enhance the life of hyperelastic materials in automotive suspension (leaf spring) system. The durability of the elastomeric (rubber) material in the insert was determined at various loading conditions for better operation. Three different rubber materials were used as the models including the currently used rubber material in the suspension system. The non-linear finite element analysis was carried out for the three different materials with the uniaxial stress–strain data as the input source for the material properties. A suitable hyperelastic model was also used as the input for determining the deformation and the stress concentration in the leaf spring tip insert. The failure of the tip insert was determined in various loading conditions and the best design for limited stress concentration with higher reliability was determined in the three models. The overall results are tabulated and compared for better utilization of rubber as a tip insert in the automotive industry.

scholarly journals Application of DIC Method in the Analysis of Stress Concentration and Plastic Zone Development Problems

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3460 ◽  
Author(s):  
Paweł J. Romanowicz ◽  
Bogdan Szybiński ◽  
Mateusz Wygoda
Keyword(s):  
Heat Treatment ◽  
Stress Concentration ◽  
High Strength Steels ◽  
High Strength ◽  
Experimental Tests ◽  
Theoretical Models ◽  
Material Behavior ◽  
Image Correlation ◽  
Stress Concentrations ◽  
Element Analysis

The paper presents the assessment of the possibility and reliability of the digital image correlation (DIC) system for engineering and scientific purposes. The studies were performed with the use of samples made of the three different materials—mild S235JR + N steel, microalloyed fine-grain S355MC steel, and high strength 41Cr4 steel subjected to different heat-treatment. The DIC studies were focused on determinations of dangerous zones with large stress concentrations, plastic deformation growth, and prediction of the failure zone. Experimental tests were carried out for samples with different notches (circular, square, and triangular openings). With the use of the DIC system and microstructure analyses, the influence of different factors (laser cutting, heat treatment, material type, notch shape, and manufacturing quality) on the material behavior were studied. For all studied cases, the stress concentration factors (SCF) were estimated with the use of the analytical formulation and the finite element analysis. It was observed that the theoretical models for calculations of the influence of the typical notches may result in not proper values of SCFs. Finally, the selected results of the total strain distributions were compared with FEM results, and good agreement was observed. All these allow the authors to conclude that the application of DIC with a common digital camera can be effectively applied for the analysis of the evolution of plastic zones and the damage detection for mild high-strength steels, as well as those normalized and quenched and tempered at higher temperatures.

scholarly journals Three-Dimensional Finite Element Analysis of Anterior Single Implant-Supported Prostheses with Different Bone Anchorages

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Fellippo Ramos Verri ◽  
Joel Ferreira Santiago Júnior ◽  
Daniel Augusto de Faria Almeida ◽  
Ana Caroline Gonçales Verri ◽  
Victor Eduardo de Souza Batista ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Anterior Region ◽  
Bone Block ◽  
Apical Region ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Biomechanical Behavior ◽  
Nasal Floor

The aim of this study was to evaluate the stress distribution of monocortical and bicortical implant placement of external hexagon connection in the anterior region of the maxilla by 3D finite element analysis (FEA). 3D models were simulated to represent a bone block of anterior region of the maxilla containing an implant (4.0 × 10.0 mm) and an implant-supported cemented metalloceramic crown of the central incisor. Different techniques were tested (monocortical, bicortical, and bicortical associated with nasal floor elevation). FEA was performed in FEMAP/NeiNastran software using loads of 178 N at 0°, 30°, and 60° in relation to implant long axis. The von Mises, maximum principal stress, and displacement maps were plotted for evaluation. Similar stress patterns were observed for all models. Oblique loads increased the stress concentration on fixation screws and in the cervical area of the implants and bone around them. Bicortical technique showed less movement tendency in the implant and its components. Cortical bone of apical region showed increase of stress concentration for bicortical techniques. Within the limitations of this study, oblique loading increased the stress concentrations for all techniques. Moreover, bicortical techniques showed the best biomechanical behavior compared with monocortical technique in the anterior maxillary area.

scholarly journals Scalloping and Stress Concentration in DRIE-Manufactured Comb-Drives

Actuators ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 57 ◽  
Author(s):  
Silvia Bertini ◽  
Matteo Verotti ◽  
Alvise Bagolini ◽  
Pierliugi Bellutti ◽  
Giuseppe Ruta ◽  
...  
Keyword(s):  
Stress Concentration ◽  
Degrees Of Freedom ◽  
Microelectromechanical Systems ◽  
Structural Complexity ◽  
Theoretical Method ◽  
Strength Loss ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Elasticity Equations ◽  
Comb Drives

In the last decades, microelectromechanical systems have been increasing their number of degrees of freedom and their structural complexity. Hence, most recently designed MEMSs have required higher mobility than in the past and higher structural strength and stability. In some applications, device thickness increased up to the order of tens (or hundred) of microns, which nowadays can be easily obtained by means of DRIE Bosch process. Unfortunately, scalloping introduces stress concentration regions in some parts of the structure. Stress concentration is a dangerous source of strength loss for the whole structure and for comb-drives actuators which may suffer from side pull-in. This paper presents an analytical approach to characterize stress concentrations in DRIE micro-machined MEMS. The method is based on the linear elasticity equations, the de Saint-Venant Principle, and the boundary value problem for the case of a torsional state of the beam. The results obtained by means of this theoretical method are then compared with those obtained by using two other methods: one based on finite difference discretization of the equations, and one based on finite element analysis (FEA). Finally, the new theoretical approach yields results which are in accordance with the known value of the stress concentration factor for asymptotically null radius notches.

Stress analysis of axisymmetric butt joints loaded in torsion and tension

1978 ◽  
Vol 13 (1) ◽  
pp. 1-10 ◽  
Author(s):  
R D Adams ◽  
J Coppendale ◽  
N A Peppiatt
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Stress Analysis ◽  
Stress Distributions ◽  
Stress Concentrations ◽  
Adhesive Properties ◽  
Butt Joints ◽  
Element Analysis ◽  
Tensile Stresses

Axisymmetric butt joints are widely used as specimens for testing the response of adhesives to shear and tensile stresses. When analysing the results from these tests, the stress distributions must be accurately known. A finite-element analysis has been used to examine the effect of non-rigid adherends and a spew fillet in solid and annular butt joints for a range of geometries and adhesive properties. It has been shown that stress concentrations occur in butt joints loaded in tension; in the latter case, the stress concentration is directly due to the presence of the spew fillet.

Proposition of Helical Thread Modeling With Accurate Geometry and Finite Element Analysis

2006 ◽  
Author(s):  
Toshimichi Fukuoka ◽  
Masataka Nomura ◽  
Yuuya Morimoto
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Contact Pressure ◽  
Three Dimensional ◽  
Bolted Joints ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Pressure Distributions ◽  
Thread Root

Distinctive mechanical behavior of bolted joints is caused by the helical shape of thread geometry. Recently, a number of papers have been published to elucidate the strength or loosening phenomena of bolted joints using three-dimensional finite element analysis. In most cases, mesh generations of the bolted joints are implemented with the help of sophisticated software. The mesh patterns so obtained are, therefore, not necessarily adequate for analyzing the stress concentration and contact pressure distributions, which are the primary concerns when designing bolted joints. In this paper, an effective mesh generation scheme is proposed, which can provide a helical thread model with accurate geometry in order to analyze such important characteristics as stress concentrations and contact pressure distributions along the thread helix. Using the FE models with accurate thread geometry, it is shown how the thread root stress and contact pressure vary along the helix and nut loaded surface and how the chamfering of the top threads of the nut mitigate the stress concentration concerned.

On the Generation of Tuned Test Problems for Stress Concentrations

2021 ◽  
Author(s):  
Glenn Sinclair ◽  
Ajay A Kardak
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Precise Determination ◽  
Test Problems ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Concentration Factors ◽  
Stress Concentration Factors

Abstract When stress concentration factors are not available in handbooks, finite element analysis has become the predominant method for determining their values. For such determinations, there is a need to know if they have sufficient accuracy. Tuned Test Problems can provide a way of assessing the accuracy of stress concentration factors found with finite elements. Here we offer a means of constructing such test problems for stress concentrations within boundaries that have local constant radii of curvature. These problems are tuned to their originating applications by sharing the same global geometries and having slightly higher peak stresses. They also have exact solutions, thereby enabling a precise determination of the errors incurred in their finite element analysis.

Stress-Distribution around Pin-Loaded Hole for Orthotropic Laminates

2016 ◽  
Vol 842 ◽  
pp. 53-60
Author(s):  
Syarif Hidayat ◽  
Bambang K. Hadi ◽  
Hendri Syamsudin ◽  
Sandro Mihradi
Keyword(s):  
Stress Concentration ◽  
Stress Distribution ◽  
Tensile Stress ◽  
Laminate Plate ◽  
Maximum Tensile Stress ◽  
Finite Width ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Edge Distance ◽  
Bearing Stress

Stresses were calculated for orthotropic laminate plate loaded by a frictionless pin in a circular hole of the same diameter. These calculations were based on finite-element analysis for five laminates; 00, [±450]s, [00/900]s,[00/±450]s, and quasi-isotropic [00/±450/900]s. stress distribution, based on nominal bearing stress, were determined for wide ranges of the ratios of width to diameter and edge distance to diameter. Orthotropic had a significant influence on both the magnitude and location of the maximum tensile stress concentration on the boundary of the hole. The laminates with 00 plies developed the peak tensile stress near the ends of the pin-hole contact arc. But the ±450 laminates had peaks where ply fiber were tangent to the hole. The finite width and edge distances strongly influenced the tensile stress concentration. In contrast, the finite widths and edge distances had little effect on bearing stress concentration. For the practical range w/d = 2, the peak tensile stresses were as much as 50 percent larger than the infinite-laminate value. For e/d=1, these stresses were greater 60 percent than infinite-laminate value. In contrast, the finite width and edge distance had little effect on bearing stress concentrations.

scholarly journals Influence of Preparation Design, Restorative Material and Load Direction on The Stress Distribution of Ceramic Veneer in Upper Central Incisor

2021 ◽  
Vol 24 (3) ◽  
Author(s):  
Laura Célia Fernandes Meirelles ◽  
Fernanda Zapater Pierre ◽  
João Paulo Mendes Tribst ◽  
Clovis Pagani ◽  
Eduardo Bresciani ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Stress Distribution ◽  
Lithium Disilicate ◽  
Occlusal Plane ◽  
Central Incisor ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Preparation Design

Objective: Evaluate the effect of four preparation designs, two ceramic materials, and two occlusion contact types on the stress distribution of ceramic veneer in upper central incisor. Material and methods:  3D-models were performed in the modeling software containing enamel, dentin, pulp, periodontal ligament and a base of polyurethane resin. The designs were modeled and exported to the computer aided engineering software to perform the static structural analysis. For the mesh, a total of 155429 tetrahedron elements and 271683 nodes were used, after a 10% convergence test. Two materials, lithium disilicate and feldspathic ceramics, were simulated. A static load of 100 N on 45º was applied on the incisal and middle thirds of the palatal tooth region, guided by the occlusal plane. The base was constrained in all directions. The Maximum Principal Stress was the failure criteria chosen for the analysis. Results: The Finite Element Analysis showed that the most conservative designs presented less stress concentration on the ceramic veneer. However, the highest tensile stress concentrations were observed on lithium disilicate veneer with extend design, on the middle third. The type of occlusal contact presented different stress patterns among the preparation designs; the incisal contact showed higher stress concentration compared to middle third contact regardless the ceramic material. Conclusions: To perform a ceramic veneer in upper central incisor, the feldspathic ceramic presented promising results and should be recommended when the extended design was done. Regarding contact types, the incisal contact is more prone to failure regardless the ceramic and preparation design.   Keywords Ceramics; Dental veneers; Finite element analysis.

Stress Concentration in Tubular Joints

1977 ◽  
Vol 17 (04) ◽  
pp. 287-299 ◽  
Author(s):  
A.B. Potvin ◽  
J.G. Kuang ◽  
R.D. Leick ◽  
J.L. Kahlich
Keyword(s):  
Stress Concentration ◽  
Computer Program ◽  
Fatigue Cracking ◽  
Offshore Structures ◽  
Parameter Study ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Analytical Technique ◽  
Tubular Joints ◽  
Hostile Environments

Abstract Fatigue cracking caused by stress concentrations in tubular joints has been observed in some fixed platforms installed in hostile environments. platforms installed in hostile environments. Consequently, the ability to assess the magnitude of the stress concentration is a Prerequisite to dealing with the fatigue problem of tubular joints. This paper deals with the problem of computing the stress concentration in three types of simple, nonreinforced joints: T-joints, K-joints, and TK-joints. Semi-empirical equations are presented for estimating the stress concentration due to axial loads and bending moments. Introduction In off shore structures stress concentrations usually occur at the intersections of tubular members (i.e., tubular joints). For some joints, the stress concentration can produce a maximum stress at the intersection as high as 20 times the nominal stress acting in the members. Stress concentrations have aggravated the fatigue of tubular joints in many existing offshore structures. Therefore, an accurate computation of stress concentrations is of utmost importance in a tubular joint design. The first part of this paper presents a discussion of the finite-element analysis method and the associated computer program developed exclusively for the analysis of tubular joints. The second part of this paper describes the parameter study carried out by means of the computer program. Formulas for estimating stress-concentration factors for simple joints commonly used in offshore structures are derived from the results of the parameter study. The usage of the resulting formulas is illustrated by a numerical example. ANALYTICAL TECHNIQUE In offshore structures such as fixed platforms and semisubmersible drilling vessels, tubular members comprise the main load-carrying components. Examples of cracking and even complete separation at the intersections of such members have been cited previously throughout the literature. A typical example of such an intersection is shown in Fig. 1. The member of greatest diameter will be referred to as the chord. The smaller diameter members framing into the chord will be called branches. The sections of the chord wall lying within the branch intersection line (if present) will be called plugs. Fig. 2 shows the various simple joint types referred to in this paper. Because of the relative complexity of the geometrical configuration of tubular intersections as well as the thin-shell theory governing their behavior, reliable prediction of the stresses in such joints by analytical techniques has proven to be costly as well as difficult. Early attempts at analysis ranged from elementary strength-of-materials approaches such as the "punching shear" method to more complicated treatments that solve the governing equations by means of Fourier Series superposition. SPEJ P. 287

Sign in / Sign up

Export Citation Format

Share Document