Analysis of Tank Car Deformations Using Multibody Systems and Finite Element Algorithms

Author(s):  
Liang Wang ◽  
Huailong Shi ◽  
Ahmed A. Shabana

This investigation demonstrates the effect of the tank flexibility and plate thickness on the wheel/rail contact and the nonlinear dynamic behavior of railroad vehicles. To this end, a flexible tank is modeled using the finite element (FE) floating frame of reference formulation (FFR). The tank car finite element model is integrated with a three-dimensional railroad vehicle using computational non-linear multibody system (MBS) framework in which the wheel/rail interaction is formulated using a three-dimensional elastic contact formulation that allows for the wheel/rail separation. A triangular shell element is used to build the tank car and describe its deformation, The effect of the coupling between different modes of displacements is demonstrated by comparing the results of the simulations of the flexible and rigid tank car models. It is shown that there is a strong dynamic coupling between different modes of displacements of the tank car, the plate thickness, and the wheel/rail contact parameters. The effect of the flexibility and plate thickness of the tank car on the vehicle critical speed and dynamic characteristics are also examined.

2016 ◽  
Vol 34 (3) ◽  
pp. 269-278 ◽  
Author(s):  
M. Yangui ◽  
S. Bouaziz ◽  
M. Taktak ◽  
M. Haddar ◽  
A. El-Sabbagh

AbstractModal analysis is developed in this paper in order to study the dynamic characteristics of rotating segmented blades assembled with spar. Accordingly, a three dimensional finite element model was built using the three node triangular shell element DKT18, which has six degrees of freedom, to model the blade and the spar structures. This study covers the effect of rotation speed and geometrically nonlinear problems on the vibration characteristics of rotating blade with various pretwist angles. Likewise, the effect of the spar in the blade is taken into consideration. The equation of motion for the finite element model is derived by using Hamilton's principle, while the resulting nonlinear equilibrium equation is solved by applying the Newmark method combined with the Newton Raphson schema. Results show that the natural frequencies increase by taking account of the spar, they are also proportional to the angular rotation speed and influenced by geometric nonlinearity and pretwist angle.


2013 ◽  
Vol 377 ◽  
pp. 3-7
Author(s):  
Ze Long You ◽  
Xiang Ming Zhang ◽  
Kui Du

An ANSYS-based "volume-spring-plate" three-dimensional finite element model is established in this paper to analyze steel plate with a rectangular hole reinforced by double-side bonding patch, in which the plate is simulated by solid45 8-node 3D element, the adhesive layer is simulated by linear elastic spring element combin14, and the patch is simulated by shell element. Relative intensity, relative stiffness and yield load rising rate of a patched steel plate with regard to parameters, such as the patch length, width, the number of patch layer and ply orientation are studied. The results indicate that composite bonded repair can effectively restore the mechanical properties of the structure and improve the service life.


Author(s):  
Martin B. Hamper ◽  
Antonio M. Recuero ◽  
José L. Escalona ◽  
Ahmed A. Shabana

Safety requirements and optimal performance of railroad vehicle systems require the use of multibody system (MBS) dynamics formulations that allow for modeling flexible bodies. This investigation will present three methods suited for the study of flexible track models while conclusions about their implementations and features are made. The first method is based on the floating frame of reference (FFR) formulation which allows for the use of a detailed finite element mesh with the component mode synthesis technique in order to obtain a reduced order model. In the second method, the flexible body is modeled as a finite number of rigid elements that are connected by springs and dampers. This method, called finite segment method (FSM) or rigid finite element method, requires the use of rigid MBS formulations only. In the third method, the FFR formulation is used to obtain a model that is equivalent to the FSM model by assuming that the rail segments are very stiff, thereby allowing the exclusion of the high frequency modes associated with the rail deformations. This FFR/FS model demonstrates that some rail movement scenarios such as gauge widening can be captured using the finite element FFR formulation. The three procedures FFR, FSM, and FFR/FS will be compared in order to establish differences among them and analyze the specific application of the FSM to modeling track flexibility. Convergence of the methods is analyzed. The three methods proposed in this investigation for modeling the movement of three-dimensional tracks are used with a three-dimensional elastic wheel/rail contact formulation that predicts contact points online and allows for updating the creepages to account for the rail deformations. Several conclusions will be drawn in view of the results obtained in this investigation.


2018 ◽  
Vol 149 ◽  
pp. 02058
Author(s):  
A. Bahaz ◽  
S. Amara ◽  
J.P. Jaspart ◽  
J.F. Demonceau

The analysis of steel-framed building structures with full strength beam to column joints is quite standard nowadays. Buildings utilizing such framing systems are widely used in design practice. However, there is a growing recognition of significant benefits in designing joints as partial strength/semi-rigid. The design of joints within this partial strength/semi-rigid approach is becoming more and more popular. This requires the knowledge of the full nonlinear moment-rotation behaviour of the joint, which is also a design parameter. The rotational behaviour of steel semi rigid connections can be studied using the finite element method for the following three reasons: i) such models are inexpensive; ii) they allow the understanding of local effects, which are difficult to measure accurately physically, and iii) they can be used to generate extensive parametric studies. This paper presents a three-dimensional finite element model using ABAQUS software in order to identify the effect of different parameters on the behaviour of semi rigid steel beam to column end plate connections. Contact and sliding between different elements, bolt pretension and geometric and material non-linearity are included in this model. A parametric study is conducted using a model of two end-plate configurations: flush and extended end plates. The studied parameters were as follows: bolts type, end plate thickness and column web stiffener. Then, the model was calibrated and validated with experimental results taken from the literature and with the model proposed by Eurocode3. The procedure for determining the moment–rotation curve using finite element analysis is also given together with a brief explanation of how the design moment resistance and the initial rotational stiffness of the joint are obtained.


Author(s):  
Hong Shen ◽  
Jun Hu ◽  
Zhenqiang Yao

Efficient laser forming modeling for industrial application is still in the developing stage and many researchers are in the process of modifying it. Conventional three-dimensional finite element models are still expensive on computational time. In this paper, a finite element model adopting a shell-solid coupling technique is developed for the thermomechanical analysis of laser forming process. In the shell-solid coupling method, an additional shell element plane is utilized to transfer heat flux and displacement from the solid elements to the shell elements. The effects of the additional interface shell element thickness on temperature distribution and final distortion are investigated. The presented shell-solid coupling method is evaluated by the results of three-dimensional simulations and experimental data.


2016 ◽  
Vol 8 (1) ◽  
pp. 25-57 ◽  
Author(s):  
Xiaoshan Lin ◽  
Mahmud Ashraf

In this study, a three-dimensional finite element model is developed to investigate the pressure–impulse response of the steel plates with semi-rigid connections under blast loads. The strain rate effect on the material properties is considered, and a number of spring elements are used for simulating the plate to support connections. Once verified, the developed finite element model is then used to investigate the effects of a series of parameters on the blast resistance and energy absorption capability of the steel plates, including the effects of connection rigidity, plate thickness, impulse loading and the shape of corrugation.


1998 ◽  
Vol 25 (3) ◽  
pp. 557-568 ◽  
Author(s):  
A Azarnejad ◽  
T M Hrudey

A numerical model is presented for the prediction of the three-dimensional stress field in an ice sheet due to temperature changes, as a function of time, under a variety of conditions. The model relies on two separate computer programs for the thermal and mechanical aspects of the problem. The thermal program uses the finite difference method to calculate the temperature distribution through the thickness of the ice cover under a variety of meteorological input conditions. The mechanical part of the analysis is conducted using the finite element method. A degenerate shell element is used, which is capable of modeling both bending and membrane behaviors of the ice cover. Relevant features of the finite element model include variable temperature and properties through the thickness, an elastic foundation representation of the underlying water, nonlinear constitutive behavior of the ice, temperature-dependent mechanical properties, flexibility of resisting structures, and boundary conditions representing a variety of shoreline types. Results are presented from simulations conducted during verification of the model. Included are simulations of uniaxial and biaxial laboratory tests on the thermal expansion of ice as well as three thermal events for which field data were available. Conclusions are presented concerning the analytical prediction of thermal ice forces.Key words: ice loads, thermal loads, ice mechanics, hydraulic structures, dams.


2011 ◽  
Vol 121-126 ◽  
pp. 1564-1569
Author(s):  
Xin Wang ◽  
Xue Xia Liu ◽  
Xu Yang Cao ◽  
Feng Zhou ◽  
Yang Zhou ◽  
...  

By reasonable assumption and considering the friction, contact, preload intensity, load eccentricity, bolt bending, and other nonlinear factors, we establish three-dimensional finite element model for the high duty bolted joint to reflect the bolt behavior and develop the finite element calculation method for static strength, fatigue strength and related stresses of bolt. By this method, we do numerous numerical simulation experiments to study the effects of preload intensity, support plate thickness on the bolt behavior. These results will guide designer to complete the slewing bearing design effectively and accurately, and these research ideas can be well applied to bolted joints study in other devices.


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.


Sign in / Sign up

Export Citation Format

Share Document