scholarly journals Tire-Rim Interaction, a Semi-Analytical Tire Model

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Federico Ballo ◽  
Giorgio Previati ◽  
Massimiliano Gobbi ◽  
Gianpiero Mastinu
Keyword(s):  
Finite Element ◽  
Stress State ◽  
Analytical Model ◽  
Lightweight Design ◽  
Experimental Tests ◽  
Tire Model ◽  
Crucial Importance ◽  
Wheel Rim ◽  
Proposed Model ◽  
Development And Validation

This paper deals with the development and validation of a semi-analytical tire model able to compute the forces at the interface between tire and rim. The knowledge of the forces acting on the rim is of crucial importance for the lightweight design of wheels. The proposed model requires a limited set of data to be calibrated. The model is compared with complete finite element (FE) models of the tire and rim. Despite its simplicity, the semi-analytical model is able to predict the forces acting on the rim, in agreement with the forces computed by complete FE models. The stress state in the wheel rim, computed by the developed semi-analytical model matches fairly well the corresponding stress state coming from experimental tests.

Motorcycle Tire Modeling for the Study of Tire–Rim Interaction

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Federico Ballo ◽  
Massimiliano Gobbi ◽  
Gianpiero Mastinu ◽  
Giorgio Previati
Keyword(s):  
Analytical Model ◽  
Good Accuracy ◽  
Lightweight Design ◽  
Experimental Tests ◽  
Contact Forces ◽  
Fem Model ◽  
Axial Forces ◽  
Wheel Rim ◽  
Wide Range ◽  
Tire Modeling

For the lightweight design of the wheel rim of motorcycles, the knowledge of the way in which contact forces are transmitted by the tire is of crucial importance. In this paper, an analytical model of the tire is developed and explicit formulae giving the distribution of the radial and axial forces acting on the wheel rim for a given vertical load are derived. The analytical model is validated by means of a finite element method (FEM) model and experimental tests. The proposed analytical model is able to predict the radial deflection of both a front and a rear tire for a racing motorbike with very good accuracy over a wide range of inflating pressures and vertical loads. The force distributions are in very good agreement with the results of the FEM model. Experimental tests show that the force distribution at the interface between the tire and rim can be used to predict the stress distribution in the rim with a good accuracy.

On the Axisymmetric Response of a Damaged Flexible Pipe

2014 ◽  
Author(s):  
José Renato M. de Sousa ◽  
Carlos Magluta ◽  
Ney Roitman ◽  
George C. Campello
Keyword(s):  
Finite Element ◽  
Analytical Model ◽  
Load Capacity ◽  
High Stress ◽  
Experimental Tests ◽  
Theoretical Models ◽  
Experimental Measurements ◽  
Fe Model ◽  
Flexible Pipe ◽  
High Stress Concentration

This work focuses on the structural analysis of a damaged 9.13″ flexible pipe to pure and combined axisymmetric loads. A set of experimental tests was carried out considering one up to ten broken wires in the outer tensile armor of the pipe and the results obtained are compared to those provided by a previously presented finite element (FE) model and a traditional analytical model. In the experimental tests, the pipe was firstly subjected to pure tension and, then, the responses to clockwise and anti-clockwise torsion superimposed with tension were investigated. In these tests, the induced strains in the outer armor were measured. Moreover, the axial elongation of the pipe was monitored when the pipe is subjected to tension, whilst the twist of the pipe was measured when torsion is imposed. The experimental results pointed to a slight decrease in the stiffness of the pipe with the increasing number of broken wires and, furthermore, a redistribution of forces among the intact wires of the damaged layer with high stress concentration in the wires close to the damaged ones. Both theoretical models captured these features, but, while the results obtained with the FE model agreed well with the experimental measurements, the traditional analytical model presented non-conservative results. Finally, the results obtained are employed to estimate the load capacity of the pipe.

New Analytical Model of Bolted Joints

2004 ◽  
Vol 126 (4) ◽  
pp. 721-728 ◽  
Author(s):  
Ouqi Zhang ◽  
Jason A. Poirier
Keyword(s):  
Finite Element ◽  
Analytical Model ◽  
External Load ◽  
Bolted Joints ◽  
Finite Element Analyses ◽  
Conventional Theory ◽  
New Model ◽  
Proposed Model ◽  
Compression Members ◽  
Additional Member

The conventional theory of bolted joints adopts equivalent cylinders, cones or spheres for compression members. In this model, the member deformation is determined by the member stiffness that remains unchanged whether the external load is present. In fact, the external load causes an additional member deformation that is not determined by the member stiffness measured at pre-load. The external load also causes a member rotation, which not only reduces the member stiffness, but also delays the separation of the joint. Based on these observations, a new model of bolted joints is developed. Finite element analyses is performed to verify the proposed model.

Motorcycle Tire Modeling

2015 ◽  
Author(s):  
Federico Ballo ◽  
Massimiliano Gobbi ◽  
Giampiero Mastinu ◽  
Giorgio Previati ◽  
Roberto Zerboni
Keyword(s):  
Analytical Model ◽  
Lightweight Design ◽  
Experimental Tests ◽  
Contact Forces ◽  
Fe Model ◽  
Actual Distribution ◽  
Axial Forces ◽  
Wide Range ◽  
Tire Modeling ◽  
Explicit Formulae

The knowledge of the actual distribution of the contact forces transmitted by the tire to the rim is of crucial importance for the lightweight design of motorcycles wheels. In this paper, an analytical model of a motorcycle tire is developed and explicit formulae giving the distribution of the static radial and axial forces acting between the tyre and the rim for a given vertical load have been derived. The analytical model has been validated by means of a FE model of the tire and wheel and on the basis of indoor experimental tests. The proposed analytical model is able to predict the radial static deflection of both a front and a rear tire for a racing motorbike with very good accuracy over a wide range of inflating pressures and vertical loads. The force distributions are in very good agreement with the results of the FE model.

scholarly journals Theoretical modeling of the vertical stiffness of a rolling lobe air spring

2020 ◽  
Vol 103 (3) ◽  
pp. 003685042094089
Author(s):  
Liufeng Xu
Keyword(s):  
Analytical Model ◽  
Ride Comfort ◽  
Experimental Tests ◽  
Geometric Parameters ◽  
Air Spring ◽  
Vertical Stiffness ◽  
Approximate Analytic Method ◽  
Proposed Model ◽  
Stiffness Characteristics ◽  
The Relationship

In order to study the characteristics of a rolling lobe air spring, a vertical stiffness analytical model is constructed based on thermodynamics and hydrodynamics. The merit of this vertical stiffness analytical model is that an analytical solution of geometric parameters is obtained by an approximate analytic method. Meanwhile, experimental tests are carried out to verify the accuracy of the vertical stiffness analytical model. The vertical stiffness analytical model can be used to qualitatively analyze the influence of geometric parameters on the vertical stiffness characteristics of a rolling lobe air spring. Therefore, the relationship between geometric parameters and the vertical stiffness characteristics is analyzed based on the proposed model. The conclusions show that the vertical stiffness analytical model can well predict the mechanical characteristics of a rolling lobe air spring and provide guidance for parameter design and vehicle ride comfort improvement.

Some Further Studies on the Axial–Torsional Behavior of Flexible Risers

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Roberto Ramos ◽  
Clóvis A. Martins ◽  
Celso P. Pesce ◽  
Francisco E. Roveri
Keyword(s):  
Finite Element ◽  
Analytical Model ◽  
Experimental Tests ◽  
Analytical Models ◽  
Analysis Tool ◽  
Full Data ◽  
Technical Literature ◽  
External Pressures ◽  
Flexible Risers ◽  
Ocean Environment

Flexible risers are complex structures composed of several concentric polymeric and steel armor layers that withstand static and dynamic loads applied by the floating production vessel and by the ocean environment. Determining the response of these structures when subjected to axisymmetric loadings (i.e., any combination of traction, torsion, and internal or external pressures) is an important task for the local structural analysis since it provides probable values for the loading distribution along the layers and, thus, allowing estimating the expected life of a riser using fatigue tools. Although finite element models have been increasingly used to accomplish this task in the last years, the simplicity and the reasonable accuracy provided by analytical models can be seen as reasons that justify their continued use, at least in the initial cycles of the design. However, any analytical model proposed for such a task must be checked with well-conducted experimental results in order to be considered as an acceptable analysis tool. The aims of this article are twofold: (i) to present the main results of experimental tests involving both internal pressure and traction loadings on a 63.5 mm (2.5 in.) flexible riser, carried out at the Institute for Technological Research of São Paulo (IPT), which can be used as a means of checking finite element or analytical models proposed by other researchers, and (ii) to compare some results obtained experimentally with those predicted by an analytical model which can also include any combination of axisymmetric loadings. Besides presenting full data concerning the internal structure of the riser, the experimental procedures used to perform the tests and the main results (e.g., Force × Displacement curves) are also presented. A brief discussion about the validity of some hypotheses that are usually assumed by analytical models found in the technical literature is made.

scholarly journals Analytical and experimental investigation of the delamination during drilling of composite structures with core drill made of diamond grits: X-ray tomography analysis

2017 ◽  
Vol 52 (10) ◽  
pp. 1281-1294 ◽  
Author(s):  
Jamel Saoudi ◽  
Redouane Zitoune ◽  
Suhasini Gururaja ◽  
Mehdi Salem ◽  
Salah Mezleni
Keyword(s):  
Carbon Fibre ◽  
Analytical Model ◽  
Composite Structures ◽  
Thrust Force ◽  
Experimental Tests ◽  
X Ray ◽  
Reinforced Plastics ◽  
The Core ◽  
Proposed Model ◽  
Critical Thrust Force

Among the various forms of material damage, exit-ply delamination has been identified as one of the most deleterious damage processes associated with drilling fibre-reinforced plastics. The thrust force has been cited as the primary cause for drilling-induced exit-ply delamination. Only one analytical model for the prediction of the critical thrust force responsible for delamination using core drills can be found in the literature. In this study, a realistic model to predict critical thrust force responsible for drilling-induced exit-ply delamination in a multi-directional carbon fibre-reinforced plastic laminate with core drill has been proposed. A comparison between the proposed model, literature model as well as the experimental tests conducted during punching tests is presented. The proposed model is found to correlate well with experimental punching tests. In fact, the maximum relative errors recorded between the experimental values of the critical thrust force and the measured values are around 15%. Micro-tomography experiments have also been conducted that capture the drilling-induced damage in multi-directional carbon fibre-reinforced plastics in great detail. The X-ray images highlight the difficulty in controlling the thickness of the uncut plies located under the core drill during punching tests that can be attributed to some deviations in predictions of critical thrust force. Postmortem examination of the blind holes after punching tests also confirms the presence of a net delamination near the vicinity of the nominal diameter of the core drill, which correlates well to the hypothesis of the analytical model.

A Simple Finite Element Based Model for a Constrained-Layer of Viscoelastic Material: Part 1 — Experimental Verification and Comparison With Analytical Models

1998 ◽  
Author(s):  
Carl Sisemore ◽  
Ahmad Smaili
Keyword(s):  
Finite Element ◽  
Analytical Model ◽  
Viscoelastic Material ◽  
Damping Ratio ◽  
Base Material ◽  
Analytical Models ◽  
Proposed Model ◽  
Experimental Values ◽  
Lumped Masses ◽  
Stiffness And Damping

Abstract In this article, a simple, finite element based model for a constrained layer of viscoelastic damping for beams is developed and implemented. The proposed model uses a series of discrete springs and dampers to model the stiffness and damping, and lumped masses to account for the mass of the viscoelastic material while the base material and constraining layers are modeled with a five-node Timoshenko beam element. The accuracy of the model is verified experimentally by testing damped beams with various damping treatment configurations. The results from the proposed model and the experiments are then compared with the Mead-Markus analytical model. Concerns over the accuracy of the Mead-Markus analytical model are raised and discussed. The results demonstrate that the proposed model can predict the fundamental natural frequency of damped beams to within 3.5% or better of the experimentally determined values and that, with the exception of short and intermediate length constraining layers, the damping ratio can be predicted to within about 8% of the experimental values under most circumstances.

scholarly journals An Extended Spring-mass Model of Single-lap Multi-bolt Composite Joints Considering Assembly Gap and Gap Shimming

2021 ◽  
Author(s):  
yuxing yang ◽  
Yongjie Bao ◽  
Jinlong Wang ◽  
Fengming Du
Keyword(s):  
Finite Element ◽  
Analytical Model ◽  
Relative Error ◽  
Joint Stiffness ◽  
Shear Stiffness ◽  
Shear Loading ◽  
Maximum Relative Error ◽  
Composite Joints ◽  
Composite Joint ◽  
Proposed Model

Abstract To investigate the effect of assembly gap and shim on single-lap multi-bolt composite joint stiffness, an analytical model based on the spring-mass method was proposed, which converted the multi-bolt joints into individual single-bolt joint based on premise that there are no overlap regions of the highly stressed portions for adjacent holes. The proposed model considers the conical and spherical stress envelope and gradual elimination phenomenon of the bolt-hole clearances for multi-bolt joints. Meantime, an effective-to-equivalent gap area method was proposed to calculate the joint stiffness for situations with arbitrary assembly gap shape. Both experiment and finite element method for three-bolt joints were used to validate the proposed model with different situations of assembly gap and/or shim. The relative error of the shear stiffness between the analytical model and experiment is 0.31%, while that of the bolt stiffness is 19.8%. After that, four interested situations with different assembly gap and/or shims were discussed, and the maximum relative error of the shear stiffness between the analytical model and the finite element model is17.0%, while that of the bolt stiffness is 15.8%. Taking into account the complexity of composite material and that of assembly gap and gap shimming, the proposed analytical model is effective to predict the stiffness of the single-lap multi-bolt composite joints subjected to single-shear loading.

scholarly journals A new analytical model to predict the formation of necking instabilities in porous plates subjected to dynamic biaxial loading

2021 ◽  
Author(s):  
Murlidhar Anil Kumar ◽  
Komi Espoir N'souglo ◽  
Jose Rodriguez-Martinez
Keyword(s):  
Finite Element ◽  
Stress State ◽  
Linear Stability ◽  
Analytical Model ◽  
Biaxial Loading ◽  
Volume Fraction ◽  
Hydrostatic Stress ◽  
Matrix Material ◽  
Loading Path ◽  
Porous Plasticity

In this paper, we have developed a linear stability analysis to predict the formation of necking instabilities in porous ductile plates subjected to dynamic biaxial stretching. The mechanical behavior of the material is described with the Gurson-Tvergaard-Needleman constitutive relation for progressively cavitating solids (Gurson, 1977; Tvergaard, 1981, 1982; Tvergaard and Needleman, 1984) which considers the voids to be spherical and the matrix material isotropic with yielding defined by the von Mises (1928) criterion. The analytical model is formulated in a two-dimensional framework in which the multiaxial stress state that develops inside the necked region is approximated with the Bridgman (1952) correction factor, superimposing a hydrostatic stress state to the uniform stress field that develops in the plate before localization. As opposed to the linear stability models published so far to model dynamic necking in ductile plates, which consider the material to be fully dense and incompressible, the approach developed in this paper provides new insights into the interplay between porosity and inertia on plastic localization. In addition, the predictions of the theoretical model for the critical strain leading to necking formation have been compared with unit-cell finite element calculations performed in ABAQUS/Explicit (2019). Satisfactory quantitative and qualitative agreement has been found between the theoretical and computational approach for loading paths ranging from plane strain tension to nearly equibiaxial tension, loading rates varying from 100 s−1 to 10000 s−1, and different values of the initial void volume fraction ranging from 0.01 to 0.1. Both analytical and finite element results suggest that the influence of porosity on necking localization increases, due to early voids coalescence, as the loading rate increases and the loading path approaches equibiaxial tension. The original formulation developed in this paper serves as a basis for analytically modeling the dynamic formability of porous ductile plates, and it can be readily extended to consider more complex porous plasticity theories, e.g. constitutive models which consider the anisotropy of the material (Benzerga and Besson, 2001) and/or voids with different shapes (Gologanu et al., 1993; Monchiet et al., 2008).

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