Optimization of the Component Characteristics for Improving Collision Safety by Simulation

2016 ◽  
pp. 79-94
Keyword(s):  
Collision Safety

A Rubber Bag for Liquid Cargo to Improve Ship Collision Safety

2016 ◽  
Author(s):  
Jan M. Kubiczek ◽  
Boyuan Liang ◽  
Lars Molter ◽  
Sören Ehlers
Keyword(s):  
Structural Design ◽  
Large Scale ◽  
Material Model ◽  
Tensile Tests ◽  
Additional Increase ◽  
Safety Level ◽  
Oil Leakage ◽  
Collision Safety ◽  
Reaction Forces ◽  
Ship Collision

Collisions and grounding accidents of ships, but also the failure of the hull-integrity, can lead to oil leakage. Examples are the Rena in 2011, the Hebei Spirit in 2007 and the much known accident of the Prestige in 2002. Consequently research regarding the enhancement of the structural design to increase the safety-level of ships in case of accidents is important. In this paper the use of a rubber bag as a second barrier is presented as an alternative concept to prevent oil leakage in case of accidents. The influence of the rubber bag is investigated using the example of a ship collision. A simplified tanker side structure as well as a box shaped rubber bag are analyzed with the finite element method. The material model for the rubber bag is calibrated with tensile tests to obtain the required material parameters. The reaction forces and the associated penetration depth are analyzed. The comparison is done between the structure with and without the rubber bag. For the latter, the general behavior is compared with large-scale experimental results. Furthermore an additional increase of the survivability of the ship due to the rubber bag without changing the common structural design is discussed.

scholarly journals Safe Joint Mechanism using torsion springs for Collision Safety and Positioning Accuracy of a Robot Arm

2020 ◽  
Author(s):  
Adel Belharet ◽  
Jae-Bok Song
Keyword(s):  
Service Robots ◽  
Robot Arm ◽  
Positioning Accuracy ◽  
External Torque ◽  
High Stiffness ◽  
Collision Safety ◽  
Passive Compliance ◽  
Joint Mechanism ◽  
Mechanical Elements ◽  
Torsion Springs

In recent years, the potential for collision between humans and robots has drawn much attention since service robots are increasingly being used in the human environment. A safe robot arm can be achieved using either an active or passive compliance method. A passive compliance system composed of purely mechanical elements often provides faster and more reliable responses to dynamic collision than an active system involving sensors and actuators. Since positioning accuracy and collision safety of a robot arm are equally important, a robot arm should have very low stiffness when subjected to a collision force capable of causing human injury. Otherwise, it should maintain a very high stiffness. To implement these requirements, a novel safe joint mechanism (SJM-IV) consisting of a CAM, rotational links with rollers, and torsion springs is proposed. The SJM-IV has the advantage of nonlinear stiffness, which can be achieved only with passive mechanical elements. Various analyses and experiments on static and dynamic collisions show high stiffness of the SJM-IV against an external torque less than a predetermined threshold torque, with an abrupt drop in stiffness when the external torque exceeds this threshold. The safe joint mechanism enables a robot manipulator to guarantee positioning accuracy and collision safety, and which is simple to install between an actuator and a robot link without a significant change in the robot’s design.

scholarly journals Study on application of MSOT method for lightweight design of automobile body structure

2020 ◽  
Vol 12 (10) ◽  
pp. 168781402096504
Author(s):  
Li Jixiong ◽  
Wang Daoyong
Keyword(s):  
Weight Reduction ◽  
Lightweight Design ◽  
The Body ◽  
Body Structure ◽  
Multi Objective Optimization ◽  
Pareto Solution ◽  
Multi Objective ◽  
Automobile Body ◽  
Collision Safety ◽  
Side Collision

In this study, the integrated MSOT (M-Multi-dimensional factor autobody model, S-Screening autobody component, O-Optimization of plate thickness, T-Testing, and validation) integration method is adopted to optimize the automobile body structure design for weight reduction. First, a multi-dimensional factor body model is established, then components of the vehicle are screened for the most important targets related to weight reduction and performance, and a multi-objective optimization is performed. Virtual experiments were carried out to validate the analysis and the MSOT method were proposed for lightweight design of the automobile body structure. A multi-dimensional performance model that considers stiffness, modality, strength, frontal offset collision, and side collision of a domestic passenger car body structure. Components affecting the weight of the vehicle were identified. Sheet metal thickness was selected as the main optimization target and a multi-objective optimization was carried out. Finally, simulations were performed on the body structure. The comprehensive performance, in terms of fatigue strength, frontal offset collision safety, and side collision safety, was verified using the optimized Pareto solution set. The results show that the established MSOT method can be used to comprehensively explore the weight reduction of the body structure, shorten the development process, and reduce development costs.

scholarly journals Simulation Analysis of Contributing Factors to Rider Visibility Issues for Car-Motorcycle Accidents

2019 ◽  
Vol 48 (3) ◽  
pp. 203-209
Author(s):  
Danish Farooq ◽  
Janos Juhasz
Keyword(s):  
Collision Avoidance ◽  
High Speed ◽  
Simulation Analysis ◽  
Point Of View ◽  
Time Interval ◽  
Contributing Factors ◽  
Depth Analysis ◽  
Collision Safety ◽  
Motorcycle Accidents ◽  
Safety Systems

Rider visibility has been considered an important issue in car-motorcycle accidents due to the frequency of unperceptive and negligent driving behavior. Mostly car drivers stated that they didn’t see the rider before the collision. This study aims to investigate the contributing factors that reduce rider visibility in point of view of car drivers for car-motorcycle accidents. The study considered the car-motorcycle accidents which occur in the built-up area. Statistical data analysis categorized the accidents into six dominant accident types. Twenty-five accidents were selected by accident types for simulation analysis. The selected accidents were simulated in Virtual Crash software during 5 seconds before the collision. The simulation analysis evaluated that the view obstructions, blind spots and high speed were the contributing factors that reduce rider visibility in car-motorcycle accidents. The simulation plots identified the involvement of contributory factors and variation within the time interval. The comprehensive in-depth analysis also evaluated that no collision avoidance maneuvers were performed by most of the car drivers due to visibility issues before the collision. Safety systems were proposed based on observed factors according to car and motorcycle perspectives for collision avoidance.

A general formulation for time-to-collision safety indicator

2013 ◽  
Vol 166 (5) ◽  
pp. 294-304 ◽  
Author(s):  
Mahmoud Saffarzadeh ◽  
Navid Nadimi ◽  
Saber Naseralavi ◽  
Amir Reza Mamdoohi
Keyword(s):  
Time To Collision ◽  
Safety Indicator ◽  
Collision Safety

Evaluation of Series Clutch Actuators With a High Torque-to-Weight Ratio for Open-Loop Torque Control and Collision Safety

2018 ◽  
Vol 3 (1) ◽  
pp. 297-304 ◽  
Author(s):  
Yushi Wang ◽  
Alexander Schmitz ◽  
Kento Kobayashi ◽  
Javier Alejandro Alvarez Lopez ◽  
Wei Wang ◽  
...  
Keyword(s):  
Weight Ratio ◽  
Open Loop ◽  
Torque Control ◽  
Collision Safety ◽  
High Torque
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