scholarly journals A novel method to derive wheel / rail wear coefficient in the field using multi-body dynamics

2021 ◽  
Author(s):  
Satoshi HARA ◽  
Masahiro KAWASAKI ◽  
Yoshiaki TERUMICHI ◽  
Katsuya TANIFUJI
Keyword(s):  
Wear Coefficient ◽  
Rail Wear ◽  
Body Dynamics ◽  
Novel Method ◽  
Multi Body

Parameter study and multi-objective optimization for crashworthiness of a B-type metro train

2021 ◽  
pp. 095440972110082
Author(s):  
Yanwen Liu ◽  
Bing Yang ◽  
Shou-ne Xiao ◽  
Tao Zhu ◽  
Guangwu Yang ◽  
...  
Keyword(s):  
Parameter Study ◽  
Multi Objective Optimization ◽  
Dynamics Model ◽  
Multi Objective ◽  
Living Space ◽  
Body Dynamics ◽  
Negative Effect ◽  
Novel Method ◽  
Multi Body ◽  
Positive Effect

A train’s crashworthiness responses are directly affected by the vehicle weight M, train collision speed V, and empty stroke D. This study investigated the influences of M, V, and D on train crashworthiness. A one-dimensional multi-body dynamics model for a B-type metro train was created and verified. Approximate models were established for the total compression displacement (TS) and overall average collision deceleration (TMA) based on M, V, and D, and a novel method was proposed for quickly predicting the output response of a train’s crashworthiness. The effects of the various parameters on TS and TMA were investigated, and a multi-objective optimization for minimizing TS and TMA was conducted. The results indicated that V has the greatest influence on TS and TMA, followed by M, and then D; M has a positive effect on TS and negative effect on TMA, whereas D has a negative effect on both TS and TMA; V has a positive effect on TS, but for TMA, the effect changes from positive to negative when V increases to 23 km/h. The optimized metro train has higher integrity in the passenger living space and a lower train collision average deceleration, and the crashworthiness is significantly improved.

scholarly journals Estimating maximum bite performance in Tyrannosaurus rex using multi-body dynamics

2012 ◽  
Vol 8 (4) ◽  
pp. 660-664 ◽  
Author(s):  
K. T. Bates ◽  
P. L. Falkingham
Keyword(s):  
Body Size ◽  
Feeding Behaviour ◽  
Ontogenetic Change ◽  
Positive Allometry ◽  
Musculoskeletal Models ◽  
Terrestrial Animal ◽  
Body Dynamics ◽  
Mode Of Life ◽  
Scaling Analyses ◽  
Multi Body

Bite mechanics and feeding behaviour in Tyrannosaurus rex are controversial. Some contend that a modest bite mechanically limited T. rex to scavenging, while others argue that high bite forces facilitated a predatory mode of life. We use dynamic musculoskeletal models to simulate maximal biting in T. rex . Models predict that adult T. rex generated sustained bite forces of 35 000–57 000 N at a single posterior tooth, by far the highest bite forces estimated for any terrestrial animal. Scaling analyses suggest that adult T. rex had a strong bite for its body size, and that bite performance increased allometrically during ontogeny. Positive allometry in bite performance during growth may have facilitated an ontogenetic change in feeding behaviour in T. rex , associated with an expansion of prey range in adults to include the largest contemporaneous animals.

Sir Robert Stawell Ball and methodologies of modern screw theory

2002 ◽  
Vol 216 (1) ◽  
pp. 1-11 ◽  
Author(s):  
H Lipkin ◽  
J Duffy
Keyword(s):  
Computational Geometry ◽  
Rigid Body ◽  
Lie Algebra ◽  
Screw Theory ◽  
Mechanical Design ◽  
Ball Screw ◽  
Dual Numbers ◽  
Body Dynamics ◽  
Rigid Body Mechanics ◽  
Multi Body

The theory of screws was largely developed by Sir Robert Stawell Ball over 100 years ago to investigate general problems in rigid body mechanics. Nowadays, screw theory is applied in many different but related forms including dual numbers, Plilcker coordinates and Lie algebra. An overview of these methodologies is presented along with a perspective on Ball. Screw theory has re-emerged after a hiatus to become an important tool in robot mechanics, mechanical design, computational geometry and multi-body dynamics.

Tanker Truck Sloshing Simulation Using Bi-Directionally Coupled CFD and Multi-Body Dynamics Solvers

2014 ◽  
Author(s):  
Michael S. Barton ◽  
David Corson ◽  
John Quigley ◽  
Babak Emami ◽  
Tanuj Kush
Keyword(s):  
Body Dynamics ◽  
Tanker Truck ◽  
Multi Body

Study of Self-Propelled Pufferfish Driven by Multiple Fins: A Comparison Between Rigid and Deformable Fins

2017 ◽  
Author(s):  
Ruoxin Li ◽  
Qing Xiao ◽  
Lijun Li ◽  
Hao Liu
Keyword(s):  
Underlying Mechanism ◽  
Operating Conditions ◽  
The Self ◽  
Fish Swimming ◽  
Propulsion Efficiency ◽  
Live Fish ◽  
Body Dynamics ◽  
Computational Fluid Dynamics Cfd ◽  
Multi Body ◽  
Better Than

In this work, we numerically studied the steady swimming of a pufferfish driven by the undulating motion of its dorsal, anal and caudal fins. The simulations are based on experimentally measured kinematics. To model the self-propelled fish swimming, a Computational Fluid Dynamics (CFD) tool was coupled with a Multi-Body-Dynamics (MBD) technique. It is widely accepted that deformable/flexible or undulating fins are better than rigid fins in terms of propulsion efficiency. To elucidate the underlying mechanism, we established an undulating fins model based on the kinematics of live fish, and conducted a simulation under the same operating conditions as rigid fins. The results presented here agree with this view by showing that the contribution of undulating fins to propulsion efficiency is significantly larger than that of rigid fins.

Sign in / Sign up

Export Citation Format

Share Document