Self-weight and Durability Analysis of Bus Body Structure using Finite Element Analysis

Author(s):  
Vikas Radhakrishna Deulgaonkar ◽  
M.S. Kulkarni ◽  
S.S. Khedkar ◽  
S.U. Kharosekar ◽  
V.U. Sadavarte

Self-weight and durability analysis of non-airconditioned sleeper bus has been carried in present work. Automotive industry standards (052 and 119) are used to freeze bus dimensions. Generative surface design is used in preparation to compute model. The bus superstructure behaviour is simulated for load on cant and waist rails for self-weight analysis. Bump analysis is carried out considering total failure of suspension system. Behaviour of bus during bump is simulated for two situations i.e. bump focre applied to front left wheel suspension location and all other suspension locations are fixed and force applied to front two wheel suspension locations and rear two wheel suspension locations are fixed. Behaviour of bus under torsional load for two cases viz first, force is applied to left of front suspension location in upward direction and other on to right suspension location in downward direction while the rear wheel suspension points are fixed and in second case, force is applied to left of front suspension in upward direction while the second one is applied to right in rear suspension location. Braking and double lane change load conditions are simulated with a braking efficiency of 80% and a lateral load of magnitude 0.4g is evaluated. Durability of the bus based on outcomes from braking, bump, torsional and double-lane change road-load situations is evaluated. The stress and deflection magnitudes are in good agreement with the results available in literature.

Author(s):  
Vikas Radhakrishna Deulgaonkar ◽  
M.S. Kulkarni ◽  
S.S. Khedkar ◽  
S.U. Kharosekar ◽  
V.U. Sadavarte

Crash analysis of non-air-conditioned sleeper bus has been carried in present work. Using relevant automotive industry standards (052 and 119) bus dimensions are considered for design. Surface modeling technique is used to prepare computer aided model. Further the bus design is freeze using finite element analysis for different crash conditions as front impact, side impact and rear impact. Crash analysis of the proposed bus design is carried using Ansys Workbench. Using the outcomes from finite element analysis as stresses, deflections, internal and kinetic energies during various crash conditions are estimated. Mesh generator is used to mesh the complex bus model. The stress and deflection magnitudes of proposed bus model are in good agreement with the experimental results available in literature. Design improvements are made using the finite element analysis outcomes, observing the deformation patterns additional pillar members of suitable length are added to increase the dynamic crush and further enhance occupant safety during collisions.


Author(s):  
Vikas Radhakrishna Deulgaonkar ◽  
M.S. Kulkarni ◽  
S.S. Khedkar ◽  
S.U. Kharosekar ◽  
V.U. Sadavarte

Present work deals with evaluation of dynamic characteristics of a bus body structure. The bus under consideration is a sleeper non-air conditioned vehicle for a passenger capacity of thirty and it is designed adhering to automotive industry standards. Modal analysis of the proposed bus design is carried using Ansys Workbench. With the aid of modal analysis ten mode shapes of the bus are postulated, corresponding frequencies and deflections are estimated. Mesh generator is used to mesh the complex bus model. The deflection and frequency magnitudes of proposed bus model is found with the help of Finite Element Analysis (FEA) technique and they are in good agreement with experimental results available in literature. Engine being the prime source of excitation, it’s frequency is compared with the frequencies determined by FEA of the proposed bus body and it is observed that the frequencies of the bus body for ten different modes are far less than the minimum resonant engine frequency.


2021 ◽  
Vol 143 (7) ◽  
Author(s):  
Icaro Bezerra Viana ◽  
Husain Kanchwala ◽  
Kenan Ahiska ◽  
Nabil Aouf

Abstract This work considers the cooperative trajectory-planning problem along a double lane change scenario for autonomous driving. In this paper, we develop two frameworks to solve this problem based on distributed model predictive control (MPC). The first approach solves a single nonlinear MPC problem. The general idea is to introduce a collision cost function in the optimization problem at the planning task to achieve a smooth and bounded collision function, and thus to prevent the need to implement tight hard constraints. The second method uses a hierarchical scheme with two main units: a trajectory-planning layer based on mixed-integer quadratic program (MIQP) computes an on-line collision-free trajectory using simplified motion dynamics, and a tracking controller unit to follow the trajectory from the higher level using the nonlinear vehicle model. Connected and automated vehicles (CAVs) sharing their planned trajectories lay the foundation of the cooperative behavior. In the tests and evaluation of the proposed methodologies, matlab-carsim cosimulation is utilized. carsim provides the high-fidelity model for the multibody vehicle dynamics. matlab-carsim conjoint simulation experiments compare both approaches for a cooperative double lane change maneuver of two vehicles moving along a one-way three-lane road with obstacles.


Author(s):  
Nathaniel Steinbock ◽  
Laura Prange ◽  
Brian C. Fabien

Emergency lane changes are often the best course of action when avoiding obstacles on the road, but this maneuver has the possibility of sending the vehicle out of control. The University of Washington EcoCAR team has a hybrid-electric vehicle outfitted with an electric drivetrain and variable torque control to each of the rear wheels. Each rear wheel has an electric motor that is independently controlled to provide torque to the wheel. A lateral vehicle dynamics model is used to develop a torque control strategy to improve the safety and maneuverability of a modified hybrid-electric 2016 Camaro as part of the EcoCAR 3 competition. The specific scenario simulated is a two-lane lane change at a speed of 55 mph. We would like to increase the yaw and lateral accelerations that the vehicle can perform safely by controlling differing torques out of the two motors. Regulating these accelerations requires a control strategy over the left and right motor torques. Equal-torque control of the electric motors will be used as a baseline.


Author(s):  
Armin Norouzi ◽  
Milad Masoumi ◽  
Ali Barari ◽  
Saina Farrokhpour Sani

In this paper, a novel Lyapunov-based robust controller by using meta-heuristic optimization algorithm has been proposed for lateral control of an autonomous vehicle. In the first step, double lane change path has been designed using a fifth-degree polynomial (quantic) function and dynamic constraints. A lane changing path planning method has been used to design the double lane change manoeuvre. In the next step, position and orientation errors have been extracted based on the two-degree-of-freedom vehicle bicycle model. A combination of sliding mode and backstepping controllers has been used to control the steering in this paper. Overall stability of the combined controller has been analytically proved by defining a Lyapunov function and based on Lyapunov stability theorem. The proposed controller includes some constant parameters which have effects on controller performance; therefore, particle swarm optimization algorithm has been used for finding optimum values of these parameters. The comparing result of the proposed controller with backstepping controller illustrated the better performance of the proposed controller, especially in the low road frictions. Simulation of designed controllers has been conducted by linking CarSim software with Matlab/Simulink which provides a nonlinear full vehicle model. The simulation was performed for manoeuvres with different durations and road frictions. The proposed controller has outperformed the backstepping controller, especially in low frictions.


Author(s):  
Adam Christopherson ◽  
Young-Hoon Han

Abstract Strain gauges provide a convenient and affordable method to accurately measure the strain field for complex systems. Not only do they provide crucial information for predicting the fatigue life of components, but they can also determine the principle stresses which can be used to compare design factors with accepted industry standards. The use of electrical resistance strain gauges for load verification has become an ever-increasing practice in the design of subsea connectors as evidenced by the recent application in the industry guidance API 17TR7 [1]. The design is aided by the development of a Finite Element Analysis (FEA) which is used to predict the load capacities for normal, extreme, and survival conditions. The present work describes the experimental validation of a 18-3/4in 10,000 psi subsea collet connector model by applying linear pattern CEA-06-062UW-350 strain gauges at discrete points along the circumferentially spaced collet segments. The collet segments are the selected components for strain gauge placement because not only are they the primary connecting element between the subsea wellhead and the connector body, but they also only support axial loads. The axial strain of the collet segments in tension were compared at two combined loading cases: maximum bending capacity with and without internal working pressure and found to be in good correlation with the elastic-plastic FEA. The experimentally validated FEA is a crucial tool in determining the connector’s application to project or customer specific load and fatigue requirements and eliminates the need for unnecessary experimentation.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yi-Chang Wu ◽  
Zi-Heng Sun

The aim of this paper is to present an innovative electromechanical device which integrates a brushless DC (BLDC) hub motor with a speed-changing wheel hub stored on the rear wheel of an electric bicycle. It combines a power source and a speed-changing mechanism to simultaneously provide functions of power generation and transmission for electric bicycles. As part of the proposed integrated device, the wheel hub consists of a basic planetary gear train providing three forward speeds including a low-speed gear, a direct drive, and a high-speed gear. Each gear is manually controlled by the shift control sleeve to selectively engage or disengage four pawl-and-ratchet clutches based on its clutching sequence table. The number of gear teeth of each gear element of the wheel hub is synthesized. The BLDC hub motor is an exterior-rotor-type permanent-magnet synchronous motor. Two-dimensional finite-element analysis (FEA) software is employed to facilitate the motor design and performance analysis. An analysis of the power transmission path at each gear is provided to verify the validity of the proposed design. The results of this work are beneficial to the embodiment, design, and development of novel electromechanical devices for the power and transmission systems of electric bicycles.


Author(s):  
Janine Woo ◽  
Muntaseer Kainat ◽  
Samer Adeeb

Current industry standards cite depth and interaction with additional stress risers as the key indicators of pipeline integrity concerns in regards to dents. There have been significant efforts towards the improvement of these benchmarks in recent years. Several dent assessment methods are presented in literature, including research focused on the use of finite element analysis (FEA). The accurate assessment of dents using FEA is heavily reliant on how close the shape produced by the FEA model aligns with the shape of the actual dent. The research presented in this paper has been conducted to evaluate the sensitivity of the stresses and strains to the dent profile shape. Information regarding the existence, shape, and size of dents is typically provided by in-line inspection (ILI) tools. An FEA model is then built in commercially available software, ABAQUS, to create a dent profile that closely resembles the profile given by the ILI. The study in this paper assesses the effect of different indenter sizes on the stresses and strains within the dent and provides a recommendation to quantify the error between the ILI and FEA profiles. The process of matching a dent profile using FEA is compared to an existing analytical method to calculate strain, the equations proposed in ASME B31.8. The FEA results were found to be more conservative than the strains calculated using ASME B31.8.


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