Optimization of a Soft Robotic Bladder Array for Dissipating High Impact Loads: an Initial Study in Designing a Smart Helmet

2020 ◽  
Author(s):  
Jonathan P. Aston ◽  
Nik Benko ◽  
Takara Truong ◽  
Alia Zaki ◽  
Nathaniel Olsen ◽  
...  
Keyword(s):  
Initial Study ◽  
High Impact ◽  
Impact Loads

Mechanism of Parameters Variation about Electronic Components Subjected to High Impact Loads

2010 ◽  
Vol 44-47 ◽  
pp. 256-259 ◽  
Author(s):  
Bo Li ◽  
Ya Zhang ◽  
Hong Xiang Zhang
Keyword(s):  
Data Collection ◽  
Stress Level ◽  
Main Parameter ◽  
High Speed ◽  
Dynamic Testing ◽  
High Impact ◽  
Impact Loads ◽  
Electronic Components ◽  
Collection System ◽  
High Speed Data

Large quantity dynamic testing experiments are carried out to testing the parameter of electronic components in high over loading impact condition with a standard hammer machine and a high speed data collection system. And the experiments were performed for about 5000 times to more than 30 types of resistors, capacitors, transistors to test their main parameter in different stress level and fixing mode. The parameter of some electronic components appears more or less unstable, namely temporary failure, and it is sensitive to different stress level and impact direct in experiments, which can offer important value of references for reliability lifespan.

scholarly journals Simulation-Based Design and Optimization of Accelerometers Subject to High-Temperature and High-Impact Loads

Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3759 ◽  
Author(s):  
Ji Li ◽  
Yaling Tian ◽  
Junjie Dan ◽  
Zhuming Bi ◽  
Jinhui Zheng ◽  
...  
Keyword(s):  
High Temperature ◽  
High Impact ◽  
Impact Loads ◽  
Sensing Element ◽  
Design And Optimization ◽  
Static And Dynamic Analysis ◽  
Simulation Based Design ◽  
Coupling Behavior ◽  
Simulation Based ◽  
Complete Failure

Due to multi-factor coupling behavior, the performance evaluation of an accelerometer subject to high-temperature and high-impact loads poses a significant challenge during its design phase. In this paper, the simulation-based method is applied to optimize the design of the accelerometer. The proposed method can reduce the uncertainties and improve the fidelity of the simulation in the sense that (i) the preloading conditions of fasteners are taken into consideration and modeled in static analysis; (ii) all types of loadings, including bolt preloads, thermal loads, and impact loads, are defined in virtual dynamic prototype of the accelerometer. It is our finding that from static and dynamic analysis, an accelerometer is exposed to the risk of malfunction and even a complete failure if the temperature rises to a certain limit; it has been proved that the thermal properties of sensing components are the most critical factors for an accelerometer to achieve its desired performance. Accordingly, we use a simulation-based method to optimize the thermal expansion coefficient of the sensing element and get the expected design objectives.

Extension velocity limiter for the ring of an elastically adaptive peripheral docking mechanism

2020 ◽  
pp. 44-55
Author(s):  
Yaroslav V. RASSKAZOV ◽  
Ivan E. CHERNYSHEV ◽  
Viktor D. KOBETS
Keyword(s):  
Friction Coefficient ◽  
High Velocity ◽  
Viscous Friction ◽  
High Impact ◽  
Ball Screw ◽  
Simplified Model ◽  
Initial Contact ◽  
Impact Loads ◽  
Ring Extension ◽  
Docking Mechanism

The docking ring of an elastically adaptive docking mechanism on the initial contact signal is extended by spring-loaded mechanisms of the rods in order to improve capture conditions. In the process, it reaches a high velocity, which applies unacceptably high impact loads to the docking interface. This paper discusses an extension velocity limiter for the docking ring, its analytical model, and a brief procedure for calculating its parameters. It describes a simplified model for ring extension during initial contact, and a method for determining viscous friction coefficient of the ball-screw pair of the docking mechanism, which is a parameter in the model. It presents the procedure, results and comparison of simulations of the docking ring extension both with the use of the proposed retarder and without it. It is demonstrated that the use of the velocity limiter permits to meet the requirements of the International Standard for pulsed loads on the passive interface. The paper describes a design option for velocity limiter that has acceptable mass and dimensions. Keywords: spacecraft docking, elastically adaptive docking mechanism, retraction device, velocity limiter, mechanical governor

Neuromuscular control in extreme high impact loads

2006 ◽  
Vol 39 ◽  
pp. S177
Author(s):  
J. Avela ◽  
M. Ishikawa ◽  
C. Nicol ◽  
P. Chavet ◽  
J. Peltonen ◽  
...  
Keyword(s):  
Neuromuscular Control ◽  
High Impact ◽  
Impact Loads

Nonlinear system identification of smart structures under high impact loads

2013 ◽  
Vol 22 (5) ◽  
pp. 055008 ◽  
Author(s):  
Kemal Sarp Arsava ◽  
Yeesock Kim ◽  
Tahar El-Korchi ◽  
Hyo Seon Park
Keyword(s):  
System Identification ◽  
Nonlinear System ◽  
Smart Structures ◽  
Nonlinear System Identification ◽  
High Impact ◽  
Impact Loads

High impact-testing machine for elastomers investigation under impact loads

2009 ◽  
Vol 28 (8) ◽  
pp. 871-874 ◽  
Author(s):  
A. Söver ◽  
L. Frormann ◽  
R. Kipscholl
Keyword(s):  
Testing Machine ◽  
High Impact ◽  
Impact Testing ◽  
Impact Loads ◽  
Impact Testing Machine

scholarly journals Reduction of Contact Forces in a Rotor-Stator-System in case of Rubbing through Active Auxiliary Bearing

2006 ◽  
Vol 13 (4-5) ◽  
pp. 505-518 ◽  
Author(s):  
Alvaro Chavez ◽  
Heinz Ulbrich ◽  
Lucas Ginzinger
Keyword(s):  
Rotating Machinery ◽  
High Impact ◽  
Contact Forces ◽  
Control Technique ◽  
Impact Loads ◽  
Control Concept ◽  
Auxiliary Bearing ◽  
Loss Of Contact ◽  
Contact Situation ◽  
Practical Feasibility

The present manuscript deals with the problem of rotor-stator rubbing. Due to performance increase in rotating machinery, rubbing processes happen more frequently. These are very complicated mechanisms that lead to high impact loads, vibrations and instability. The authors propose a control technique by using an active auxiliary bearing to overcome the problem of rubbing. The control concept enables a transition of the rotor towards a contact situation (with an auxiliary bearing) without rebounding and loss of contact. To investigate the practical feasibility of this approach, numerical simulation has been used to show that using this control concept the impulse (and contact force respectively) can be significantly decreased. Experiments to validate the theoretical findings are already in progress and will be published soon.

Performance Assessment of an Impact Rig

1988 ◽  
Vol 202 (4) ◽  
pp. 275-285 ◽  
Author(s):  
R S Birch ◽  
N Jones ◽  
W S Jouri
Keyword(s):  
Mathematical Modelling ◽  
Performance Assessment ◽  
High Impact ◽  
Energy Losses ◽  
Impact Loads ◽  
Test Results ◽  
Drop Hammer

A recent upgrading of a drop hammer rig was carried out and a series of calibration tests established the energy losses in the existing anvil. Both the test results and the mathematical modelling showed that significant energy losses would occur at high impact loads. An alternative anvil design considerably reduced the energy losses and improved the performance of the drop hammer rig.

scholarly journals Particle Swarm Optimization for Active Structural Control of Highway Bridges Subjected to Impact Loading

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Jake Edmond Hughes ◽  
Yeesock Kim ◽  
Jo Woon Chong ◽  
Changwon Kim
Keyword(s):  
Pid Control ◽  
Structural Control ◽  
Highway Bridges ◽  
High Impact ◽  
Highway Bridge ◽  
Impact Loads ◽  
Bridge Structure ◽  
Swarm Optimization ◽  
Active Structural Control ◽  
Control Devices

The application of active structural control technology to highway bridge structures subjected to high-impact loadings is investigated. The effects of high-impact loads on infrastructure, like heavy vehicle collisions with bridge piers, have not been studied as much as seismic load effects on structures. Due to this lack of research regarding impact loads and structural control, a focused study on the application of active control devices to infrastructure after impact events can provide valuable results and conclusions. This research applies active structural control to an idealized two-span, continuous girder, concrete highway bridge structure. The idealization of a highway bridge structure as a two degree-of-freedom structural system is used to investigate the effectiveness of control devices installed between the bridge pier and deck, the two degrees of freedom. The control devices are fixed to bracing between the bridge pier and girders and controlled by the proportional-integral-derivative (PID) control. The PID control gains are optimized by both the Ziegler–Nichols ultimate sensitivity method (USM) and a new method for this impact load application called particle swarm optimization (PSO). The controlled time-domain responses are compared to the uncontrolled responses, and the effectiveness of PID control, USM optimization, and PSO is compared for this control device configuration. The results of this investigation show PID control to be effective for minimizing both superstructure and substructure responses of highway bridges after high-impact loads. Deck response reductions of greater than 19% and 37% were seen for displacement and acceleration responses, respectively, regardless of the performance index used to analyze them. PSO was much more effective than USM optimization for tuning PID control gains.

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