scholarly journals Stability Analysis of Long Combination Vehicles Using Davies Method

2020 ◽  
Author(s):  
Gonzalo Guillermo Moreno Contreras ◽  
Rodrigo de Souza Vieira ◽  
Daniel Martins
Keyword(s):  
Load Capacity ◽  
Slope Angle ◽  
Three Dimensional ◽  
Vehicle Stability ◽  
Transport Costs ◽  
Gravity Center ◽  
The Road ◽  
Mechanism Model ◽  
Longitudinal Slope ◽  
Three Dimensional Models

The cargo transportation in the world is mostly dominated by road transport, using long combination vehicles (LCV’s). These vehicles offer more load capacity, which reduces transport costs and thus increases the efficiency and competitiveness of companies and the country. But the tradeoff of LCV’s is their low lateral stability and propensity to roll over, which has been the focus of many studies. Most vehicle stability models do not consider the longitudinal aspects of the vehicle and the road, such as the stiffness of the chassis, the gravity center location, and the longitudinal slope angle of the road. But, the use of three-dimensional models of vehicles allows a more rigorous analysis of vehicle stability. In this context, this study aims to develop a three-dimensional mechanism model representing the last trailer unit of an LCV under an increasing lateral load until it reaches the rollover threshold. The proposed model considers the gravity center movement of the trailer, which is affected by the suspension, tires, fifth-wheel, and the chassis. Davies method has proved to be an important tool in the kinetostatic analysis of mechanisms, and therefore it is employed for the kinetostatic analysis of the three-dimensional mechanism of the trailer.

Procedural Generation of Road Paths for Driving Simulation

2015 ◽  
Vol 6 (2) ◽  
pp. 37-55 ◽  
Author(s):  
Carlos Campos ◽  
João Miguel Leitão ◽  
António Fernando Coelho
Keyword(s):  
Traffic Engineering ◽  
Three Dimensional ◽  
Scientific Work ◽  
Driving Simulation ◽  
Driving Simulators ◽  
Design Standards ◽  
Road Engineering ◽  
The Road ◽  
Procedural Generation ◽  
Three Dimensional Models

Virtual environments for driving simulation aimed to scientific purposes require realistic three-dimensional models of roads. The creation of road models for these purposes, is usually preceded by the design of road paths which fulfill all the desired specific characteristics. Traditionally, the design of road paths is performed by road engineering specialists, resulting in a very time-consuming task. This paper presents a method that allows the procedural generation of road paths aimed to driving simulation experiments (e.g., ergonomics, psychology and traffic engineering). This method is inspired in methods used in roadways engineering, producing roads according to the design standards and similar to those found in the real world. This significantly reduces the need of specialists to prepare the road paths and generate road models suitable for conducting scientific work in driving simulators.

Structural Synthesis and Analysis of Mechanisms with an Output Link Performing Two Rotational and One Translational Movements

2021 ◽  
pp. 43-49
Author(s):  
A.I. Edakin ◽  
T.V. Edakina ◽  
V.V. Samoilova ◽  
V.S. Ramzhaev
Keyword(s):  
Load Capacity ◽  
Three Dimensional ◽  
Kinematic Pair ◽  
Structural Synthesis ◽  
Output Link ◽  
Plasma Properties ◽  
Belt Drives ◽  
Pair Mating ◽  
Three Dimensional Models ◽  
Surgical Operations

The article considers mechanisms based on a hinged flat parallelogram with an additional link, ensuring the ability to maintain the insertion point of the tool installed on the output link. A rotational kinematic pair coupled to the base allows the plane of rotation of the articulated parallelogram to change the angle of inclination. The proposed design should have a greater load capacity than the available analogues, since the rotational kinematic pair mating the articulated parallelogram with the base is made in the form of two semi-axes, and the output link is located between the intermediate links of this parallelogram. The equality of the rotation angles of the output link and the intermediate links of the articulated parallelogram is ensured by the presence of additional links or belt drives. Three-dimensional models of these mechanisms are presented, and their structural synthesis is carried out in various modifications. Depending on the modification, it becomes possible to apply such mechanisms not only in industry, including additive technologies, but also in the field of medicine during surgical operations and in the study of plasma properties.

Remeshing Technique for Three Dimensional Finite Element in ABAQUS

2011 ◽  
Vol 71-78 ◽  
pp. 4147-4150
Author(s):  
Chun Guang Wang ◽  
Cong Chen ◽  
Wei Wang ◽  
Hong Bin Shi ◽  
Hong Chao Liu
Keyword(s):  
Finite Element ◽  
Load Capacity ◽  
Three Dimensional ◽  
Compression Process ◽  
Mesh Distortion ◽  
Element Simulation ◽  
Dimensional Finite Element ◽  
Three Dimensional Models ◽  
Three Dimensional Finite Element ◽  
Sharp Corners

To resolve the divergence problems in three-dimensional finite element simulation caused by the mesh distortion,put forward a three-dimensional remeshing technique in ABAQUS by making use of the good interface between ABAQUS and HYPERMESH.Simulated a rubber block compression process using this technique.The results show that:1). the grid distortion at sharp corners has been improved significantly and this remeshing technique can attain reliable results,especially in three-dimensional models with the large deformation;2). the initial analysis load capacity should be reasonably determined in order to obtain the better remeshing results.This technique can resolve the problems brought by the mesh distortion very well.

scholarly journals Framework for 3D Point Cloud Modelling Aimed at Road Sight Distance Estimations

2019 ◽  
Vol 11 (23) ◽  
pp. 2730
Author(s):  
González-Gómez ◽  
Iglesias ◽  
Rodríguez-Solano ◽  
Castro
Keyword(s):  
Point Cloud ◽  
Three Dimensional ◽  
The Road ◽  
3D Objects ◽  
Sight Distance ◽  
Road Geometry ◽  
Three Dimensional Models ◽  
The Individual ◽  
Periodic Evaluation ◽  
Cloud Modelling

Existing roads require periodic evaluation in order to ensure safe transportation. Estimations of the available sight distance (ASD) are fundamental to make sure motorists have sufficient visibility to perform basic driving tasks. Mobile LiDAR Systems (MLS) can provide these evaluations with accurate three-dimensional models of the road and surroundings. Similarly, Geographic Information System (GIS) tools have been employed to obtain ASD. Due to the fact that widespread GIS formats used to store digital surface models handle elevation as an attribute of location, the presented methodology has separated the representation of ground and aboveground elements. The road geometry and surrounding ground are stored in digital terrain models (DTM). Correspondingly, abutting vegetation, manmade structures, road assets and other roadside elements are stored in 3D objects and placed on top of the DTM. Both the DTM and 3D objects are accurately obtained from a denoised and classified LiDAR point cloud. Based on the consideration that roadside utilities and most manmade structures are well-defined geometric elements, some visual obstructions are extracted and/or replaced with 3D objects from online warehouses. Different evaluations carried out with this method highlight the tradeoff between the accuracy of the estimations, performance and geometric complexity as well as the benefits of the individual consideration of road assets.

Research on Influence of Longitudinal Gradient to Rigid Base Composite Road of Cross River (Sea) Tunnel under Large Longitudinal Slope

2011 ◽  
Vol 189-193 ◽  
pp. 1621-1624
Author(s):  
Jun Fu ◽  
Yu Qin ◽  
Qing Jun Ding
Keyword(s):  
Model Calculation ◽  
Slope Angle ◽  
Three Dimensional ◽  
Great Influence ◽  
Rigid Base ◽  
Longitudinal Gradient ◽  
Fem Model ◽  
Cross River ◽  
Longitudinal Slope ◽  
Base Composite

The influences of longitudinal gradient on the large longitudinal slope rigid base composite road of cross river(sea) tunnel are concerned recently. Then the relationships between sheering stresses versus slope angle, load, pavement depth, interlayer touch condition and modulus are discussed separately by a three dimensional FEM model. Calculation and analysis showed: gradient had great influence on the surface tangent load and little influence on design deflection, the base and surface.The maximum tension and sheer on surface were increased with the gradient. On general, the gradient and surface tangent load should be considered in structure analysis for the large longitudinal slope road.

Plastic replicas as three-dimensional models of pulps

1975 ◽  
Vol 39 (8) ◽  
pp. 544-546
Author(s):  
HL Wakkerman ◽  
GS The ◽  
AJ Spanauf
Keyword(s):  
Three Dimensional ◽  
Dimensional Models ◽  
Three Dimensional Models

Low-Degree Tibial Slope Angle Prevents Component Overhang by Enlarging the Lateral Plateau Surface Area in Total Knee Arthroplasty

2020 ◽  
Author(s):  
Mehmet Emin Simsek ◽  
Mustafa Akkaya ◽  
Safa Gursoy ◽  
Özgür Kaya ◽  
Murat Bozkurt
Keyword(s):  
Total Knee Arthroplasty ◽  
Surface Area ◽  
Knee Arthroplasty ◽  
Tibial Plateau ◽  
Slope Angle ◽  
Three Dimensional ◽  
Tibial Slope ◽  
Total Knee ◽  
Lateral Plateau ◽  
Gender Groups

AbstractThis study aimed to investigate whether overhang or underhang around the tibial component that occurs during the placement of tibial baseplates was affected by different slope angles of the tibial plateau and determine the changes in the lateral and medial plateau diameters while changing the slope angle in total knee arthroplasty. Three-dimensional tibia models were reconstructed using the computed tomography scans of 120 tibial dry bones. Tibial plateau slope cuts were performed with 9, 7, 5, 3, and 0 degrees of slope angles 2-mm below the subchondral bone in the deepest point of the medial plateau. Total, lateral, and medial tibial plateau areas and overhang/underhang rates were measured at each cut level. Digital implantations of the asymmetric and symmetric tibial baseplates were made on the tibial plateau with each slope angles. Following the implantations, the slope angle that prevents overhang or underhang at the bone border and the slope angle that has more surface area was identified. A significant increase was noted in the total tibial surface area, lateral plateau surface area, and lateral anteroposterior distance, whereas the slope cut angles were changed from 9 to 0 degrees in both gender groups. It was found that the amount of posteromedial underhang and posterolateral overhang increased in both the asymmetric and symmetric tibial baseplates when the slope angle was changed from 0 to 9 degrees. Although the mediolateral diameter did not change after the proximal tibia cuts at different slope angles, the surface area and anteroposterior diameter of the lateral plateau could change, leading to increased lateral plateau area. Although prosthesis designs are highly compatible with the tibial surface area, it should be noted that the component overhangs, especially beyond the posterolateral edge, it can be prevented by changing the slope cut angle in males and females.

Validation of a Belt Model for Prediction of Hub Forces from a Rolling Tire4

2009 ◽  
Vol 37 (2) ◽  
pp. 62-102 ◽  
Author(s):  
C. Lecomte ◽  
W. R. Graham ◽  
D. J. O’Boy
Keyword(s):  
Internal Pressure ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Prediction Method ◽  
Analytical Models ◽  
Beam Model ◽  
Impedance Boundary ◽  
Bending Waves ◽  
Tire Rotation ◽  
Three Dimensional Models

Abstract An integrated model is under development which will be able to predict the interior noise due to the vibrations of a rolling tire structurally transmitted to the hub of a vehicle. Here, the tire belt model used as part of this prediction method is first briefly presented and discussed, and it is then compared to other models available in the literature. This component will be linked to the tread blocks through normal and tangential forces and to the sidewalls through impedance boundary conditions. The tire belt is modeled as an orthotropic cylindrical ring of negligible thickness with rotational effects, internal pressure, and prestresses included. The associated equations of motion are derived by a variational approach and are investigated for both unforced and forced motions. The model supports extensional and bending waves, which are believed to be the important features to correctly predict the hub forces in the midfrequency (50–500 Hz) range of interest. The predicted waves and forced responses of a benchmark structure are compared to the predictions of several alternative analytical models: two three dimensional models that can support multiple isotropic layers, one of these models include curvature and the other one is flat; a one-dimensional beam model which does not consider axial variations; and several shell models. Finally, the effects of internal pressure, prestress, curvature, and tire rotation on free waves are discussed.

In Silico Identification and Molecular Characterization of Extracellular Cathepsin L Proteases from Giardia duodenalis

2020 ◽  
Vol 17 (4) ◽  
pp. 342-351
Author(s):  
Sergio A. Durán-Pérez ◽  
José G. Rendón-Maldonado ◽  
Lucio de Jesús Hernandez-Diaz ◽  
Annete I. Apodaca-Medina ◽  
Maribel Jiménez-Edeza ◽  
...  
Keyword(s):  
In Silico ◽  
Cathepsin L ◽  
Three Dimensional ◽  
Giardia Duodenalis ◽  
Evolutionary Genetics ◽  
Extracellular Proteins ◽  
In Silico Identification ◽  
Dimensional Models ◽  
Three Dimensional Models

Background: The protozoan Giardia duodenalis, which causes giardiasis, is an intestinal parasite that commonly affects humans, mainly pre-school children. Although there are asymptomatic cases, the main clinical features are chronic and acute diarrhea, nausea, abdominal pain, and malabsorption syndrome. Little is currently known about the virulence of the parasite, but some cases of chronic gastrointestinal alterations post-infection have been reported even when the infection was asymptomatic, suggesting that the cathepsin L proteases of the parasite may be involved in the damage at the level of the gastrointestinal mucosa. Objective: The aim of this study was the in silico identification and characterization of extracellular cathepsin L proteases in the proteome of G. duodenalis. Methods: The NP_001903 sequence of cathepsin L protease from Homo sapienswas searched against the Giardia duodenalisproteome. The subcellular localization of Giardia duodenaliscathepsin L proteases was performed in the DeepLoc-1.0 server. The construction of a phylogenetic tree of the extracellular proteins was carried out using the Molecular Evolutionary Genetics Analysis software (MEGA X). The Robetta server was used for the construction of the three-dimensional models. The search for possible inhibitors of the extracellular cathepsin L proteases of Giardia duodenaliswas performed by entering the three-dimensional structures in the FINDSITEcomb drug discovery tool. Results: Based on the amino acid sequence of cathepsin L from Homo sapiens, 8 protein sequences were identified that have in their modular structure the Pept_C1A domain characteristic of cathepsins and two of these proteins (XP_001704423 and XP_001704424) are located extracellularly. Threedimensional models were designed for both extracellular proteins and several inhibitory ligands with a score greater than 0.9 were identified. In vitrostudies are required to corroborate if these two extracellular proteins play a role in the virulence of Giardia duodenalisand to discover ligands that may be useful as therapeutic targets that interfere in the mechanism of pathogenesis generated by the parasite. Conclusion: In silicoanalysis identified two proteins in the Giardia duodenalisprotein repertoire whose characteristics allowed them to be classified as cathepsin L proteases, which may be secreted into the extracellular medium to act as virulence factors. Three-dimensional models of both proteins allowed the identification of inhibitory ligands with a high score. The results suggest that administration of those compounds might be used to block the endopeptidase activity of the extracellular cathepsin L proteases, interfering with the mechanisms of pathogenesis of the protozoan parasite Giardia duodenalis.

Sign in / Sign up

Export Citation Format

Share Document