Analysis of Whole Weathered Granite Improved Soil Subgrade Dynamic Response

2013 ◽  
Vol 723 ◽  
pp. 261-267
Author(s):  
Wen Yi ◽  
Teng Pan ◽  
Ai Jun Chen
Keyword(s):  
Numerical Simulation ◽  
Dynamic Response ◽  
Test Data ◽  
Dynamic Load ◽  
High Speed ◽  
Simulation Analysis ◽  
Load Test ◽  
Simulation Data ◽  
Software Simulation ◽  
Repeated Load

In this paper, strain and displacement for FLAC3D numerical simulation analysis of the whole weathering granite improved soil subgrade in train dynamic load of the stress is conducted, subgrade under repeated load test data and software simulation data is contrasted, the center of subgrade vertical settlement and the center of the subgrade stress change situation is researched.Through the research proves the whole weathering improved soil subgrade can ensure the high-speed safety, comfort and use requirement.

Experiment and Research of Using Fiber Bragg Grating to Monitor the Dynamic Response of Asphalt Concrete

2011 ◽  
Vol 97-98 ◽  
pp. 301-304 ◽  
Author(s):  
Ke Li ◽  
Jian Guang Xie
Keyword(s):  
Dynamic Response ◽  
Fiber Bragg Grating ◽  
Asphalt Concrete ◽  
High Speed ◽  
Load Test ◽  
Bragg Grating ◽  
Static Load Test ◽  
Practical Applications ◽  
Fbg Sensor ◽  
On The Road

Based on the fiber Bragg grating sensing technology, a FBG sensor is designed to monitor the dynamic response of asphalt concrete; the sensitivity coefficient of FBG sensor is 1.28pm/με. Through the static load test, the correlation between strain and wavelength variation is 0.1797µε/pm, after second packaged and embedded in SMA-13 asphalt concrete. The instantaneous impact on the road of high-speed vehicles is simulated by using drop hammer. The results are shown that the Sensor can satisfy the requirements of practical applications and succeed in monitoring the dynamic response of asphalt concrete. The monitored signal can reflect the viscoelastic-plastic deformation law of asphalt concrete. The sensor can be used to monitor the dynamic response of asphalt concrete.

The Application Research on the Elastic-Flexible Anchor in the Retaining Wall

2012 ◽  
Vol 594-597 ◽  
pp. 255-258
Author(s):  
Lin Gao ◽  
Yan Shi ◽  
Guo Qiang Xu
Keyword(s):  
Numerical Simulation ◽  
Dynamic Load ◽  
Simulation Analysis ◽  
Retaining Wall ◽  
Deformable Body ◽  
Application Research ◽  
Buffering Effect ◽  
New Type ◽  
The Common ◽  
Stress And Deformation

The anchor which added a elastic-flexible deformable body on the common anchor will be form a new type anchor, it is called the elastic-flexible anchor. With the help of FLAC3D 3.0, we compared the numerical simulation analysis results between the common anchor and the elastic-flexible anchor. we obtained that, the elastic-flexible anchor has the higher bearing capacity and more excellent anti-deformation performance, this mainly due to the elastic-flexible deformable body which has the buffering effect of the stress and deformation. The results confirmed the elastic-flexible anchor especially applied to the support structure with the requirements of large deformation and dynamic load, and worth popularizing in the anchor retaining wall engineering.

Typical Brackets Dimensional Numerical Simulation of the Wooden Structure

2014 ◽  
Vol 1008-1009 ◽  
pp. 1250-1253
Author(s):  
Wei Chao Ao ◽  
Qing Fang Niu ◽  
Guan Feng Qiao ◽  
Tie Ying Li
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Dynamic Response ◽  
Failure Modes ◽  
Simulation Analysis ◽  
Dual Function ◽  
Finite Element Software ◽  
The Ancient Chinese ◽  
Mechanism Of Failure ◽  
Architectural Ornament

Brackets is the ancient Chinese wooden building unique ways and one of the main features of the structure. Its dual function of both structural and architectural: An important component of both the structure itself, because of its flexible features tenon, the dynamic response of the structure can absorb greater energy, play a good role in the earthquake; But it is also a special architectural ornament, can play the effect of beautifying buildings. Therefore, this paper based on the finite element software ABAQUS brackets by the force of the mechanism of failure modes and numerical simulation analysis for the brackets and the whole structure of the wood to provide a scientific assessment and reinforcement.

Design of the Wind Channel for the Test-Bed of Aerodynamic Brake

2013 ◽  
Vol 275-277 ◽  
pp. 584-589
Author(s):  
Meng Ting Cheng ◽  
Chun Tian ◽  
Meng Ling Wu ◽  
Ying Xi
Keyword(s):  
Flow Field ◽  
High Speed ◽  
Simulation Analysis ◽  
Wind Load ◽  
Load Test ◽  
Test Bed ◽  
Speed Flow ◽  
Aerodynamic Brake ◽  
Opening And Closing ◽  
Load Size

For simulating the wind load strength effect so as to detect the opening and closing performance of the aerodynamic braking device and the reliability of its opening and closing mechanism with the wind load caused by high speed flow field, the wind load test-bed is to build. Wind channel, as the equipment to turn a high pressure flow into a relatively high speed advection, is one of its important components. This paper focuses on the design of the shape of the wind channel. By the means of flow field simulation analysis, with the indexes of the wind load size, the pressure distribution and the flow equality, the shape optimization of the wind channel is realized.

Numerical Simulation of Dynamically Loaded Flexible Short Journal Bearings

1985 ◽  
Vol 107 (3) ◽  
pp. 396-401 ◽  
Author(s):  
L. van der Tempel ◽  
H. Moes ◽  
R. Bosma
Keyword(s):  
Numerical Simulation ◽  
Differential Equations ◽  
Numerical Method ◽  
Dynamic Load ◽  
High Speed ◽  
Journal Bearings ◽  
Combustion Engines ◽  
Dynamically Loaded ◽  
Newton Raphson ◽  
Raphson Method

A numerical method is proposed for calculating film thicknesses in flexible short journal bearings under dynamic load. The system of elastohydrodynamic integro-differential equations is discretized directly and solved by a 2-step Newton-Raphson method. The cavitation boundaries are located by a special discretization of the pressure. This type of condition puts practically no restrictions on the boundary alterations. The results for the con rod bearings of medium- and high-speed combustion engines are compared.

Simulation Based Design and Optimization of Digital Pump/Motors

2013 ◽  
Author(s):  
Kyle J. Merrill ◽  
Farid Y. Breidi ◽  
John Lumkes
Keyword(s):  
Dynamic Response ◽  
High Speed ◽  
Simulation Analysis ◽  
Significant Loss ◽  
Operating Characteristics ◽  
Flow Ripple ◽  
Design And Optimization ◽  
Piston Cylinder ◽  
Operating Strategies ◽  
Design Tradeoffs

Current state of the art variable displacement pump/motors have high efficiencies when operating at high displacements. However, as the displacement of the pump/motor is reduced, the efficiency significantly decreases. Digital pump/motors aim to increase the efficiency and range of operation of the fluid power system by minimizing leakages, friction losses and compressibility losses. It is based on the concept of actively controlling high speed on/off valves connected to each piston cylinder displacement chamber. This work involves the development of a coupled dynamic model of a digital hydraulic pump/motor that is crucial for understanding the design tradeoffs and operating characteristics of the digital pump/motor. This simulation model can be used to characterize and predict the efficiency, define the dynamic response and flow requirements of on/off valves required to provide significant improvements in efficiency and dynamic response over traditional pump/motors, and perform design optimization studies. The model can analyze different operating strategies (flow limiting and flow diverting) and characterize the effects on pump/motor efficiency and flow ripple. The simulation analysis shows that the sequential flow limiting strategy yields the lowest power loss in both pumping and motoring and that small variances in the valve response would cause a significant loss of power.

Study on the Distributed and Non-Stationary Dynamic Load Being Transformed into Several Equivalent Centralized Loads for Aerocraft

2011 ◽  
Vol 105-107 ◽  
pp. 965-968
Author(s):  
Xiao Tong Chang ◽  
Yun Ju Yan
Keyword(s):  
Numerical Simulation ◽  
Theoretical Analysis ◽  
Dynamic Load ◽  
High Speed ◽  
Vibration Test ◽  
Feasible Method ◽  
Distributed Load

Missiles always undergo non-stationary and continuously distributed load. However, only some centralized loads can be adopted in the ground for their vibration experiments. In this paper, the theoretical analysis and numerical simulation computations programs are established for the distributed and non-stationary airdynamic load being translated into several equivalent centralized loads for high-speed missile. The researches showed that, under the equivalent rule of structural modal responses, the average responses error in both domains time and frequency is within 1.5dB, so it is possible to provide a feasible method for the vibration test on the ground for missile structures.

Influence of contact loss underneath concrete underlayer on dynamic performance of prefabricated concrete slab track

2016 ◽  
Vol 231 (3) ◽  
pp. 345-358 ◽  
Author(s):  
Ren Juanjuan ◽  
Yang Rongshan ◽  
Wang Ping ◽  
Dai Feng ◽  
Yan Xiaobo
Keyword(s):  
Numerical Simulation ◽  
Dynamic Response ◽  
High Speed ◽  
Critical Value ◽  
Short Wave ◽  
Dominant Factor ◽  
Track Structure ◽  
Slab Track ◽  
Actual Contact ◽  
Long Wave

Contact loss between the concrete underlayer and the subgrade caused by the differential settlement or stiffness of subgrade structure is a common distress, which deteriorates the mechanical properties of the track structure and adversely affects the safety and comfort for the operation on high-speed railway. The objective of this paper is to study the damage mechanism of prefabricated slab track subjected to such contact loss and to propose a critical value for the size of contact loss that would not jeopardize the safety of rail traffic and riding comfort of passengers. Thus, a vibration calculation model for the vertically coupled vehicle-J-slab track-subgrade system is established using finite element method, both of the short-wave irregularity and the German long-wave irregularity were taken into account to calculate the dynamic response of vehicle, track structure and subgrade with different contact loss areas and speeds scenarios. Based on the numerical simulation results, a critical value of contact loss area is proposed. When the actual contact loss area is smaller than the critical value, the welded joint irregularity is the dominant factor in the vehicle dynamic response; however, when the actual contact loss area is larger than the critical value, the track irregularity induced by contact loss under the concrete underlayer becomes the dominant factor. It is suggested that the contact loss area should be controlled under the critical value in order to ease or mitigate the dynamic response of the vehicle and track structure. The numerical simulation indicates the critical contact loss area is about 10 m2 for the short-wave irregularity case and 14 m2 for the long-wave irregularity case, thus it is suggested that the contact loss area underneath the concrete underlayer should not exceed 10 m2, which is consistent with the Swedish standard and the German standard on weak areas of subgrade compaction.

scholarly journals Numerical Simulation Analysis of an Oversteer In-Wheel Small Electric Vehicle Integrated with Four-Wheel Drive and Independent Steering

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Muhammad Izhar Ishak ◽  
Hirohiko Ogino ◽  
Yoshio Yamamoto
Keyword(s):  
Numerical Simulation ◽  
Steady State ◽  
Critical Velocity ◽  
High Speed ◽  
Simulation Analysis ◽  
Stability Limit ◽  
Conventional Vehicle ◽  
Wheel Drive ◽  
On The Road ◽  
Four Wheel Drive

Similar to conventional vehicle, most in-wheel small EVs that exist today are designed with understeer (US) characteristic. They are safer on the road but possess poor cornering performance. With recent in-wheel motor and steer-by wire technology, high cornering performance vehicle does not limit to sport or racing cars. We believe that oversteer (OS) design approach for in-wheel small EV can increase the steering performance of the vehicle. However, one disadvantage is that OS vehicle has a stability limit velocity. In this paper, we proposed a Four-Wheel Drive and Independent Steering (4WDIS) for in-wheel small EV with OS characteristic. The aim of implementing 4WDIS is to develop a high steer controllability and stability of the EV at any velocity. This paper analyses the performance of OS in-wheel small EV with 4WDIS by using numerical simulation. Two cornering conditions were simulated which are (1) steady-state cornering at below critical velocity and (2) steady-state cornering over critical velocity. The objective of the simulation is to understand the behavior of OS in-wheel small EV and the advantages of implementing the 4WDIS. The results show that an in-wheel small EV can achieve high cornering performance at low speed while maintaining stability at high speed.

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