SIDE FORCE ANALYSIS OF SUSPENSION STRUT UNDER VARIOUS LOAD CASES

2016 ◽  
Vol 78 (6-10) ◽  
Author(s):  
Y.S. Kong ◽  
S. Abdullah ◽  
M.Z. Omar ◽  
S.M. Haris
Keyword(s):  
Multibody Dynamics ◽  
Ride Comfort ◽  
Model Simulation ◽  
Bending Moment ◽  
Severe Condition ◽  
Extreme Load ◽  
Friction Analysis ◽  
Multibody Dynamics Model ◽  
Macpherson Strut ◽  
Suspension Strut

This paper presents the side forces extraction of a Macpherson suspension strut under extreme load cases using multibody dynamics model. Inevitable side forces subjected to the Macpherson suspension system during vehicle driving cause the damper rod and top mounting failure. Bending moment generated could increase the friction of damper piston and inner tube and simultaneously decrease the ride comfort of the vehicle, or in a more severe condition, failure occurs. In this study, the side forces magnitude subjected to the Macpherson strut under various severe load events were obtained through a quasi-static multibody dynamics half vehicle model simulation. Outcomes of the multibody simulation that showing the forces exerted on the suspension Macpherson strut were derived into three axes which were vertical, lateral and longitudinal. The lateral and longitudinal side forces on the strut were highest during the pothole striking event which achieved 11052 N. The extracted force provided useful information for suspension linkages design and damper friction analysis to prevent failure. 

Effect of unsupported sleepers on dynamic behavior of running vehicles and ride comfort index

2021 ◽  
pp. 095440622198937
Author(s):  
Mojtaba Azizi ◽  
Majid Shahravi ◽  
Jabbar-Ali Zakeri
Keyword(s):  
Numerical Model ◽  
Dynamic Behavior ◽  
Multibody Dynamics ◽  
Field Test ◽  
Ride Comfort ◽  
Vehicle Speed ◽  
Comfort Index ◽  
Railway Industry ◽  
Flexible Track ◽  
Train Speed

Nowadays, with various advancements in the railway industry and increasing speed of trains, the design of railway tracks and vehicles has become vitally important. One of the frequent problems of ballasted tracks is the existence of unsupported sleepers. This phenomenon occurs due to the lack of ballast underneath the sleepers. Here, a model is presented, in which a flexible track model in a multibody dynamics program is developed, in order to study the dynamic behavior of a vehicle. By utilizing the model, it is feasible to simulate unsupported sleepers on the flexible track including rail, sleeper, and ballast components. In order to verify the results of numerical model, a field test is performed. Findings indicate that, in the case of a single unsupported sleeper through the track, the ride comfort index increased by 100% after increasing the train speed from 30 to 110 km/h. Moreover, when it is needed to have ride comfort index improvement over the uncomfortable level, the vehicle speed should be less than 70 km/h and 50 km/h for tracks with one unsupported sleeper and two unsupported sleepers, respectively.

scholarly journals Multibody Dynamics Model and Simulation for the Totally Enclosed Lifeboat Lowered From Ship in Rough Seas

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 32171-32187
Author(s):  
Shaoyang Qiu ◽  
Hongxiang Ren ◽  
Haijiang Li ◽  
Yi Zhou ◽  
Delong Wang
Keyword(s):  
Multibody Dynamics ◽  
Dynamics Model ◽  
Model And Simulation ◽  
Multibody Dynamics Model

scholarly journals Strategies of traversing obstacles and the simulation for a forestry chassis

2018 ◽  
Vol 15 (3) ◽  
pp. 172988141877390 ◽  
Author(s):  
Yue Zhu ◽  
Jiangming Kan ◽  
Wenbin Li ◽  
Feng Kang
Keyword(s):  
Multibody Dynamics ◽  
Inclination Angle ◽  
Degrees Of Freedom ◽  
Ride Comfort ◽  
Hydraulic Cylinder ◽  
Single Side ◽  
Simulation Results ◽  
Maximum Inclination ◽  
Three Degrees Of Freedom ◽  
Small Inclination

As to the complicated terrain in forest, forestry chassis with an articulated body with three degrees of freedom and installed luffing wheel-legs (FC-3DOF&LW) is a novel chassis that can surmount obstacles. In addition, the rear frame of FC-3DOF&LW is regarded as the platform to carry equipment. Small inclination angle for rear frame contributes to stability and ride comfort. This article describes the strategy of traversing obstacles and simulation for FC-3DOF&LW that drives in forest terrain. First, key structures of FC-3DOF&LW are briefly introduced, which include articulated structure with three degrees of freedom and luffing wheel-leg. Based on the sketch of luffing wheel-leg, the movement range of luffing wheel-leg is obtained by hydraulic cylinder operation. Second, the strategy of crossing obstacles that are simplified three models of terrain is presented, and the simulation for surmounting obstacles is constructed in multibody dynamics software. The simulation results demonstrate that the inclination angle of rear frame is 18° when slope is 30°. A maximum 12° decrease of inclination angle for rear frame can be acquired when luffing wheel-legs are applied. For traversing obstacles with both sides, the maximum inclination angle of rear frame is about 1.2° and is only 3° for traversing obstacles with single side.

scholarly journals Multibody dynamics model of head and neck function in Allosaurus (Dinosauria, Theropoda)

10.26879/338 ◽  
2013 ◽  
Vol 16 (2) ◽  
Author(s):  
Eric Snively ◽  
John R. Cotton ◽  
Ryan Ridgely ◽  
Lawrence M. Witmer
Keyword(s):  
Head And Neck ◽  
Multibody Dynamics ◽  
Dynamics Model ◽  
Neck Function ◽  
Multibody Dynamics Model

Characterisation of a Simplified Aeroengine Casing Subjected to a Radial Loading Condition Using FE and Approximate Methods

2006 ◽  
Author(s):  
Sabesan Rajaratnam ◽  
Tom H. Hyde ◽  
Sean B. Leen
Keyword(s):  
High Reliability ◽  
High Stress ◽  
Bending Moment ◽  
Local Stress ◽  
Load Path ◽  
Approximate Methods ◽  
Loading Mode ◽  
Structure Changes ◽  
Extreme Load ◽  
Radial Loading

In general, aeroegine casings may experience an axial force, a bending-moment and radial loading. Under these loads, the high stress regions of these complex aerongine casings will experience local stress and strain concentrations, with various load combinations. The stiffness will also depend on the loading mode. Hence, careful design is required to avoid the various types of failure such as buckling, crack initiation and propagation must be taken into account when designing an aeroengine casing structure. In addition, aerongine casings require extremely high reliability in service and adequate strength under extreme load conditions, i.e. Fan-Blade-Off (FBO) condition, must be demonstrated. Under radial loading of aeroengine casings, which have spoke to shell connections, these are the most likely sites for plastic deformation to occur and cracks to initiate. Also, the load path for each spoke to shell connection within the casing structure changes during loading. Based on these observations, this paper concentrates on the behavior which occurs in spoke to shell connections, referred to as local joints. The intention is first to characterize the local joint behavior and then to incorporate this into a global casing model. The work reported in this paper includes studies of mesh sensitivity, predictions of load path at each local joint under radial load, FE failure loci, upper bound techniques for predicting limit loads and stresses-strains predictions at local casing notches under elastic-plastic and creep situations using approximate notch methods. Hence, the global responses of a casing structure were predicted by utilizing a “repeated local joint” technique in conjunction with simplified global models.

Extreme load estimation of the wind turbine tower during power production

2019 ◽  
pp. 0309524X1987276
Author(s):  
Atsushi Yamaguchi ◽  
Prasanti Widyasih Sarli ◽  
Takeshi Ishihara
Keyword(s):  
Bending Moment ◽  
Power Production ◽  
Data Sets ◽  
Bending Moments ◽  
Recurrence Period ◽  
Wind Turbine Tower ◽  
Extreme Load ◽  
Predicted Values ◽  
New Criterion ◽  
Good Agreement

Wind turbines have to be designed against extreme load during power production with the recurrence period of 50 years. This extreme load is usually calculated through statistical extrapolation. However, large uncertainties exist in the estimation of the extreme load. This study aims to reduce these uncertainties in the statistical extrapolation by using systematic simulations. First, a new criterion is proposed for the data sets to be used for the statistical extrapolation and the resulting uncertainty satisfies the requirement in the standard for prediction of wind load. Then, a new extrapolation factor for load extrapolation is proposed and the predicted maximum tower bending moments at all the heights show favorable agreement with measurement. Finally, empirical formulae are proposed to estimate the expected value of the maximum tower bending moment and the predicted values show good agreement with the numerical simulations.

Mathematical Modelling and Simulation of Heat Dispersion Due to Fire and Explosion

2012 ◽  
Author(s):  
Wan Piang Lim ◽  
Arshad Ahmad
Keyword(s):  
Heat Flux ◽  
Finite Difference ◽  
Chemical Engineering ◽  
Model Simulation ◽  
Fire Hazard ◽  
Transfer Model ◽  
Severe Condition ◽  
Heat Dispersion ◽  
Fire And Explosion ◽  
The Impact

Kebakaran dan letupan adalah antara bahaya yang kerap berlaku dalam operasi loji kimia. Dalam kertas kerja ini, perbincangan ditumpukan terhadap model matematik serakan haba yang berpunca daripada kebakaran dan letupan. Model yang diselaku berasaskan MATLAB ini menggunakan kaedah perbezaan terhingga bagi menyelesaikan masalah yang berkaitan dengan fluks haba dan suhu. Tiga kelas kebakaran telah dipertimbangkan, iaitu kebakaran kolam, kebakaran kilat dan bebola api yang berkait dengan Cecair Didih mengembangkan Wap (BLEVE). Program penyelakuan ini digunakan untuk mengkaji kesan ketiga-tiga bahaya kebakaran tersebut yang diandaikan berlaku di kemudahan storan LPG, Loji Pandu Kejuruteraan Kimia, Universiti Teknologi Malaysia. Keputusan penyelakuan menunjukkan bahawa bebola api menyebabkan berlakunya mala petaka yang paling serius dengan kematian mencapai sehingga jarak 300 meter. Kata kunci: kebakaran; model pemindahan haba; penyelakuan; pengagihan fluks haba dan suhu. Fire and explosion are among the commonly occurring major hazards in the operation of chemical plants. In this paper, a mathematical model for heat dispersion in the event of an industrial fire and explosion is presented. The model is simulated numeracally within MATLAB environment to provide both the time and space dependence of the heat flux and temperature using a finite difference method. Three classes of fire were considered. These are pool fire, flash fire and fireball following the event of Boiling Liquid Expanding Vapour (BLEVE). The simulation program that has been developed is employed to study the impact of the three types of fire hazard on a LPG storage facility at the Chemical Engineering Pilot Plant in The Universiti Teknologi Malaysia. Thre results obtained highlights the various hazard condition for all the three events, with fireball imiposing the most severe condition by having safety distance of 300 meters away from the source of release, within which fatalities are expected. Key words: Fire; heat transfer model; simulation; temperature and heat flux distribution; finite difference

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