A STUDY ON STRAIN RATE EFFECT IN COLLISION ANALYSIS OF ROLLING STOCK

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1423-1430 ◽  
Author(s):  
SEUNG ROK KIM ◽  
JEONG SEO KOO
Keyword(s):  
Strain Rate ◽  
High Speed ◽  
Dynamic Models ◽  
Strain Rate Effect ◽  
Rate Effect ◽  
Rolling Stock ◽  
Rigid Mass ◽  
Dynamic Components ◽  
Multi Body ◽  
Crash Response

In this paper, the strain rate effect of energy absorption members in rolling stock is studied using the virtual testing model (VTM) for Korean high speed train (KHST). The VTM of KHST was simulated for two different strain rate conditions. The VTM is composed of FE models for structures, and nonlinear spring/damper models for dynamic components. To simplify numerical model for the full rake KHST, the first three units consist of full flexible multi-body dynamic models, and the remainder does 1-D spring/damper/mass models. To evaluate the strain rate effect of KHST, the crash simulation was performed under the accident scenario for a collision with a rigid mass of 15 tons at 110kph. The numerical results show that the overall crash response of the train is not largely affected as much as expected, but individual components have some different deformations according to strain rate. The deformation of the front end structure without strain rate effect is larger than that with it. However, the deformation of the rear end structure without strain rate effect is smaller than that with it. Finally, the intrusion of the driver's cabin is overestimated for no strain rate effect when compared to the case with it.

scholarly journals Fracture Initiation in Notched Specimens Subjected to Compression: Strain Rate Effect

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2613
Author(s):  
Elżbieta Bura ◽  
Andrzej Seweryn
Keyword(s):  
Strain Rate ◽  
High Speed ◽  
Fracture Process ◽  
Fracture Initiation ◽  
Strain Rate Effect ◽  
Rate Effect ◽  
Specimen Thickness ◽  
Strain Rates ◽  
Notched Specimens ◽  
Compression Strain

This paper shows the results of an experimental investigation on fracture in polymethyl methacrylate (PMMA) notched specimens subjected to compression (with unloading) including different strain rates. Three types of notches were used. Flat specimens were weakened by two types of V-notches and U-notches. Additionally, two specimen thicknesses were used (9.7 and 14.5 mm). The load was carried out at the strain rate of 8 × 10−4, 4 × 10−3, and 2 × 10−2 s−1 and the unloading stage was conducted ten times faster, i.e., 8 × 10−3, 4 × 10−2, and 2 × 10−1 s−1, respectively. By using a PHANTOM high-speed camera, fracture initiation moments and locations were indicated. Two types of crack were observed and distinguished as A-type and B-type. The first was formed by the contact stress of the closing notch surfaces, while the latter was formed by the residual stresses during the unloading stage. The type of notch, specimen thickness, and the strain rate have a significant influence on the fracture process. The strain rate has a large impact on the critical load value, which determines the fracture initiation, but does not affect the location and shape of the crack. The strain rate effect usually disappears with increasing specimen thickness.

scholarly journals Dynamic Fracture Process and Strain Rate Effect of a Porous SiC Ceramic

Proceedings ◽  
2018 ◽  
Vol 2 (8) ◽  
pp. 509 ◽  
Author(s):  
Yanpei Wang ◽  
Ding Zhou ◽  
Huifang Liu ◽  
Sheikh Muhamamd Zakir ◽  
Yulong Li
Keyword(s):  
Compressive Strength ◽  
Strain Rate ◽  
Dynamic Loading ◽  
Dynamic Fracture ◽  
High Speed ◽  
Fracture Process ◽  
Strain Rate Effect ◽  
Rate Effect ◽  
Sic Ceramic ◽  
Porous Sic

In this paper, dynamic fracture process and strain rate effect of a porous SiC ceramic were investigated. The failure process under dynamic loading conditions was monitored by a high-speed camera. Digital image correlation (DIC) method was further utilized to calculate the surface strain field. The high-speed images show that crack initiates in the center of the specimen and then propagates to the entire specimen under dynamic loading. In addition, DIC result showed that cracks occur on the surface of the specimen formed a band. And the band finally caused the collapse of the specimen. The test results showed that compressive strength of the porous SiC ceramic is rate sensitive. Under quasi-static conditions, the compressive strength is about 120 MPa, while in dynamic conditions strength increased to 247 MPa. Energy absorption during the deformation process is much larger under dynamic loading.

Strain rate effect in high-speed wire drawing process

2002 ◽  
Vol 10 (3) ◽  
pp. 267-276 ◽  
Author(s):  
S He ◽  
P Van Houtte ◽  
A Van Bael ◽  
F Mei ◽  
A Sarban ◽  
...  
Keyword(s):  
Strain Rate ◽  
High Speed ◽  
Wire Drawing ◽  
Strain Rate Effect ◽  
Rate Effect ◽  
Drawing Process

Strain-rate effect on the tensile behaviour of concrete at different relative humidity levels

10.1617/13528 ◽  
2005 ◽  
Vol 34 (235) ◽  
pp. 21-26 ◽  
Author(s):  
E. Cadoni
Keyword(s):  
Relative Humidity ◽  
Strain Rate ◽  
Strain Rate Effect ◽  
Rate Effect ◽  
Tensile Behaviour

Tension, compression, and shear behavior of advanced sheet molding compound (A-SMC): Multi-scale damage analysis and strain rate effect

2021 ◽  
pp. 109287
Author(s):  
Mohammadali Shirinbayan ◽  
Hassan Beigi Rizi ◽  
Navideh Abbasnezhad ◽  
Abbas Tcharkhtchi ◽  
Joseph Fitoussi
Keyword(s):  
Strain Rate ◽  
Shear Behavior ◽  
Strain Rate Effect ◽  
Rate Effect ◽  
Damage Analysis ◽  
Compound A ◽  
Molding Compound ◽  
Sheet Molding Compound ◽  
Multi Scale

Study of the Strain Rate Effect on Cold-Reduced Carbon Steel and Aluminium Alloy with Numerical Simulations

2006 ◽  
Vol 532-533 ◽  
pp. 973-976
Author(s):  
Lin Wang ◽  
Tai Chiu Lee ◽  
Luen Chow Chan
Keyword(s):  
Carbon Steel ◽  
Strain Rate ◽  
Strain Path ◽  
Plastic Material ◽  
Strain Rate Effect ◽  
Rate Effect ◽  
Forming Process ◽  
Risk Area ◽  
Sensitive Material ◽  
Simulation Results

In this paper, the effect of strain rate has been considered in the simulation of forming process with a simple form combined into the material law. Quite a few researchers have proposed various hardening laws and strain rate functions to describe the material tensile curve. In this study, the strain rate model Cowper-Symonds is used with anisotropic elasto-plastic material law in the simulation process. The strain path evolution of certain elements, when the strain rate is considered and not, is compared. Two sheet materials, Cold-reduced Carbon Steel (SPCC) JIS G3141 and Aluminum alloy 6112 are used in this study. Two yield criteria, Hill 48 and Hill 90, are applied respectively to improve the accuracy of simulation result. They show different performance when strain rate effect is considered. Strain path of the elements in the fracture risk area of SPCC (JIS G3141) varies much when the strain rate material law is used. There is only little difference of the strain distribution of Al 6112 when the strain rate effect is included and excluded in the material law. The simulation results of material SPCC under two conditions indicate that the strain rate should be considered if the material is the rate-sensitive material, which provides more accurate simulation results.

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