scholarly journals Dynamic Finite Element Analysis of Flexible Double Wishbone Suspension Systems with Different Damping Mechanisms

Author(s):  
Alaa Adel Rahman ◽  
Ayman E Nabawy ◽  
Ayman M Abdelhaleem ◽  
Soliman S Alieldin

Suspension systems in running vehicles keep the occupants comfortable and isolated from road noise, disturbances, and vibrations and consequently prevent the vehicle from damage and wearing. To attain comfortable and vibration isolation conditions, both material flexibility and damping should be considered in the considered suspension model. This paper presents an incremental finite element model to study and analyze the dynamic behavior of double wishbone suspension systems considering both material flexibility and damping effects. The flexibility of the suspension links are modeled with plane frame element based on Timoshenko beam hypothesis (TBH). On the other hand, the flexibility of joints connecting the suspension links together and with the vehicle chassis is modeled with the revolute joint element. To incorporate the damping effect, viscoelastic, viscous and proportional damping are considered. An incremental viscoelastic constitutive relations, suitable for finite element implementation, are developed. The developed finite element equations of motion are solved using the Newmark technique. The developed procedure is verified by comparing the obtained results with that obtained by the developed analytical solution and an excellent agreement is found. The applicability and effectiveness of the developed procedure are demonstrated by conducting parametric studies to show the effects of the road irregularities profiles, the vehicle speed, and the material damping on the transverse deflection and the resultant stresses of suspension system. Results obtained are supportive in the mechanical design, manufacturing processes of such type of structural systems.

2018 ◽  
Vol 880 ◽  
pp. 163-170
Author(s):  
Ștefan Cristian Castravete ◽  
Gabriel Cătălin Marinescu ◽  
Nicolae Dumitru ◽  
Oana Victoria Oţăt

The paper studies the behavior of a quarter-car suspension model under periodic road excitation: sinusoidal and bump (trapezoidal shape) for a constant vehicle speed. A theoretical and a finite element model were developed. The theoretical model has two degrees of freedom and a modal and sinusoidal excitation was performed to compare with finite model analysis. The finite element analysis consists of three parts: preload, modal analysis and deterministic external excitation. The study consists of the analysis of forces, displacements and accelerations that are transmitted to the vehicle regarding their variation in time and frequency.


2019 ◽  
Vol 11 (05) ◽  
pp. 1950044 ◽  
Author(s):  
Ayman E. Nabawy ◽  
Alaa A. Abdelrahman ◽  
Waleed S. Abdalla ◽  
Ayman M. Abdelhaleem ◽  
Soliman S. Alieldin

Suspension systems are essential in vehicles to provide both passenger comfort and vibration isolation from road bumps. It is necessary to develop a comprehensive numerical model to study and analyze the dynamic behavior of these systems. This study aims to introduce a comprehensive finite element model to investigate the dynamic behavior of double wishbone vehicle suspension system considering links flexibility. Plane frame element based on Timoshenko beam theory (TBT) is adopted to model the suspension links. Flexibility of the joints connecting the suspension links are modeled using the revolute joint element. Viscoelastic, viscous and proportional damping models are considered to simulate the damping effect. Newmark technique, as unconditionally stable technique is adopted to solve the finite element dynamic equation of motion. The developed procedure is verified by comparing the obtained results with the available analytical and numerical results and an excellent agreement is found. To demonstrate the effectiveness of the developed model, parametric studies are conducted to show the effects of the road bump profiles, the vehicle speed, and the material damping on the dynamic behavior of suspension system. The obtained results are supportive in the design and manufacturing processes of such suspension systems.


2012 ◽  
Vol 166-169 ◽  
pp. 510-513
Author(s):  
Man Zhi Yang ◽  
Zhi Feng Peng ◽  
Fang Liu ◽  
Yi Liang Peng ◽  
Xiao Ling Sun

A medium speed mill-foundation coupled finite element model was established using ANSYS. The modal and harmonic responses of medium-speed mill were analyzed. The influence of the number of vibration isolators and the ratio of foundation bedplate to equipment on the vibration of mill was analyzed. The shock absorption measures of medium-speed mills were discussed. To get good vibration isolation effect, the maximum horizontal vibration displacement of medium-speed mill with spring vibration-isolated foundation is suggested as 50 μm, and the ratio of foundation bedplate to equipment as 3.0±0.2.


2018 ◽  
Vol 165 ◽  
pp. 16011
Author(s):  
Todor Zhelyazov ◽  
Rajesh Rupakhety ◽  
Simon Olafsson

The contribution is focused on the numerical modelling, simulation and analysis of a lead-core bearing device for passive seismic isolation. An accurate finite element model of a lead-core bearing device is presented. The model is designed to analyse both mechanical and thermo-mechanical responses of the seismic isolator to different loading conditions. Specifically, the mechanical behaviour in a typical identification test is simulated. The response of the lead-core bearing device to circular sinusoidal paths is analysed. The obtained shear displacement – shear force relationship is compared to experimental data found in literature sources. The hypothesis that heating of the lead-core during cyclic loading affects the degrading phenomena in the bearing device is taken into account. Constitutive laws are defined for each material: lead, rubber and steel. Both predefined constitutive laws (in the used general–purpose finite element code) and semi-analytical procedures aimed at a more accurate modelling of the constitutive relations are tested. The results obtained by finite element analysis are to be further used to calibrate a macroscopic model of the lead-core bearing device seen as a single-degree-of-freedom mechanical system.


1990 ◽  
Vol 112 (2) ◽  
pp. 175-182 ◽  
Author(s):  
Zhijia Yang ◽  
J. P. Sadler

A finite element model is derived for flexible planar linkages, treating the total mechanism displacements as the primary unknowns in the dynamic equations of motion. These displacements consist of the combination of large rigid-body mechanism motion and small elastic deformations. Beam elements are used in the model formulation. The resulting nonlinear equations can be solved under conditions of either specified input motion of the mechanism or specified input forcing functions. In either case, the differential equations are integrated numerically. Illustrative examples are presented, and comparisons are made with results of previous investigators and with results from a commercial finite element code.


2001 ◽  
Author(s):  
Veli-Matti Järvenpää ◽  
Erno K. Keskinen

Abstract In this paper a finite element model of a rotating paper machine roll for nip unit rolling contact analyses is discussed. This work presented here is based on the earlier work of the authors presented in [1] and [2]. The major motivations for developing a tailored FE-model including the large spin rotation are firstly to include the complex vibration phenomena as the shell vibrations of the roll structure in the analyses and secondly to reduce the computational costs of the numerical simulations due to the large number of degrees of freedom. The approach used is the use of the modal analysis i.e. to express the dynamics of the roll in terms of the lowest eigenmodes. The equations of motion are at first written in the rotating coordinates and then in addition to this the equations are expressed by using the modal coordinates. Numerical tests executed show that this modeling technique reduces computational costs significantly. Furthermore, use of the (semidefinite) eigenmode basis maintains the vibration characteristics of the roll structure. For verification purposes a test model was constructed and these simulation results were compared to the standard geometrically non-linear finite element analysis.


2011 ◽  
Vol 94-96 ◽  
pp. 500-503 ◽  
Author(s):  
Li Liu ◽  
Ji Bin Yi ◽  
Fang Wang

This paper adopts the ANSYS software to establish the profiled steel sheet and concrete composite slab finite element model. Numerical simulation is made to the composite slab in the whole process from initial loading to loading failure with reasonable Stimulation material and constitutive relations. The result of the calculation shows that promoting the strength of the concrete can largely promote the bearing capacity of the concrete, and the influence of the strength grade of the profiled steel sheet to the bearing capacity of the composite slab is smaller. The experimental result and test result accord well, testifying the reasonability of the established finite element and provide new method and way for simulating the load bearing process of composite slab.


Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.


1996 ◽  
Vol 24 (4) ◽  
pp. 339-348 ◽  
Author(s):  
R. M. V. Pidaparti

Abstract A three-dimensional (3D) beam finite element model was developed to investigate the torsional stiffness of a twisted steel-reinforced cord-rubber belt structure. The present 3D beam element takes into account the coupled extension, bending, and twisting deformations characteristic of the complex behavior of cord-rubber composite structures. The extension-twisting coupling due to the twisted nature of the cords was also considered in the finite element model. The results of torsional stiffness obtained from the finite element analysis for twisted cords and the two-ply steel cord-rubber belt structure are compared to the experimental data and other alternate solutions available in the literature. The effects of cord orientation, anisotropy, and rubber core surrounding the twisted cords on the torsional stiffness properties are presented and discussed.


2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.


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