The Mechanics of Dynamic Fiber Push-Out: Experimental and Numerical Study

2001 ◽  
Author(s):  
John Lambros ◽  
Xiaopeng Bi ◽  
Philippe H. Geubelle
Keyword(s):  
Split Hopkinson Pressure Bar ◽  
Numerical Study ◽  
Fiber Composite ◽  
Failure Process ◽  
Hopkinson Pressure Bar ◽  
Composite Systems ◽  
Initiation And Propagation ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
Push Out

Abstract This paper summarizes our recent progress on the experimental and numerical study of dynamic debonding and frictional push-out in composite systems. A modified split Hopkinson pressure bar system is adopted to perform dynamic fiber push-out experiments on model single fiber composite systems. A cohesive/volumetric finite element scheme is developed to capture the initiation and propagation of the crack along the fiber/matrix interface. Interface properties are extracted by comparison between experimental and numerical results. Effects of loading rate and surface roughness are presented. The results indicate that the combination of the experimental and numerical analysis constitutes a valuable tool to study the failure process in composites under high loading rates.

Dynamic Compression Test of CFRP Laminates Using SHPB Technique

2014 ◽  
Vol 566 ◽  
pp. 122-127
Author(s):  
Takayuki Kusaka ◽  
Takanori Kono ◽  
Yasutoshi Nomura ◽  
Hiroki Wakabayashi
Keyword(s):  
Compressive Strength ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Failure Process ◽  
Compression Tests ◽  
Hopkinson Pressure Bar ◽  
Stress Strain ◽  
Cfrp Laminates ◽  
Split Hopkinson ◽  
Pressure Bar

A novel experimental method was proposed for characterizing the compressive properties of composite materials under impact loading. Split Hopkinson pressure bar system was employed to carry out the dynamic compression tests. The dynamic stress-strain relations could be precisely estimated by the proposed method, where the ramped input, generated by the plastic deformation of a zinc buffer, was effective to reduce the oscillation of the stress field in the specimen. The longitudinal strain of gage area could be estimated from the nominal deformation of gage area, and consequently the failure process could be grasped in detail from the stress-strain relation. The dynamic compressive strength of the material was slightly higher than the static compressive strength. In addition, the validity of the proposed method was confirmed by the computational and experimental results.

Numerical Study of Round-Robin Tests on the Split Hopkinson Pressure Bar Technique

2013 ◽  
Vol 535-536 ◽  
pp. 518-521 ◽  
Author(s):  
Muhammad A. Kariem ◽  
Dong Ruan ◽  
John H. Beynon
Keyword(s):  
Split Hopkinson Pressure Bar ◽  
Numerical Study ◽  
High Strength ◽  
Round Robin ◽  
Hopkinson Pressure Bar ◽  
Element Analysis ◽  
Acceptable Error ◽  
Aisi 4140 ◽  
Split Hopkinson ◽  
Pressure Bar

It is known that the split Hopkinson pressure bar (SHPB) technique has not been standardised yet. The standardised SHPB technique is necessary in order to provide guidelines for determining the intrinsic material properties. This paper examines whether consistent results can be achieved from various sets of SHPBs. Finite element analysis has been conducted using ANSYS/LS-DYNA. Numerical simulation of the round-robin tests was conducted to study the consistency of results for OFHC copper, which were obtained from three sets of apparatus, namely: 12.7 mm diameter SHPB made from the AISI 4140 steel, 13 mm diameter SHPB made from the high strength steel (HSS) and 14.5 mm diameter SHPB made from maraging steel 350 (AISI 18Ni). The current study shows that consistent flow stresses (within an acceptable error of 2.5%) were obtained from those three sets of SHPBs, which indicates the possibility of SHPB standardisation in the future.

scholarly journals Numerical study for determination of pulse shaping design variables in SHPB apparatus

2013 ◽  
Vol 61 (2) ◽  
pp. 459-466 ◽  
Author(s):  
P. Baranowski ◽  
J. Malachowski ◽  
R. Gieleta ◽  
K. Damaziak ◽  
L. Mazurkiewicz ◽  
...  
Keyword(s):  
Pulse Shaping ◽  
Split Hopkinson Pressure Bar ◽  
Numerical Study ◽  
Experimental Tests ◽  
Peak Shape ◽  
Hopkinson Pressure Bar ◽  
Design Variables ◽  
Split Hopkinson ◽  
Pulse Peak ◽  
Pressure Bar

Abstract High strain rate experimental tests are essential in a development process of materials under strongly dynamic conditions. For such a dynamic loading the Split Hopkinson Pressure Bar (SHPB) has been widely used to investigate dynamic behaviour of various materials. It was found that for different materials various shapes of a generated wave are desired. This paper presents a parametric study of Split Hopkinson Pressure Bar in order to find striker’s design variables, which influence the pulse peak shape in the incident bar. With experimental data given it was possible to verify the developed numerical model, which was used for presented investigations. Dynamic numerical simulations were performed using explicit LS-Dyna code with a quasi-optimization process carried out using LS-Opt software in order to find striker’s design variables, which influence the pulse peak shape.

Numerical study of the specimen size effect in the split Hopkinson pressure bar tests

1995 ◽  
Vol 30 (18) ◽  
pp. 4720-4725 ◽  
Author(s):  
J. Rodr�guez ◽  
R. Cort�s ◽  
M. A. Mart�nez ◽  
V. S�nchez-G�lvez ◽  
C. Navarro
Keyword(s):  
Size Effect ◽  
Split Hopkinson Pressure Bar ◽  
Numerical Study ◽  
Specimen Size ◽  
Hopkinson Pressure Bar ◽  
Split Hopkinson ◽  
Pressure Bar

Analysis of the Impact of the Frequency Range of the Tensometer Bridge and Projectile Geometry on the Results of Measurements by the Split Hopkinson Pressure Bar Method

2013 ◽  
Vol 20 (4) ◽  
pp. 555-564 ◽  
Author(s):  
Wojciech Moćko
Keyword(s):  
Test Bench ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Deformation ◽  
Spectral Width ◽  
Hopkinson Pressure Bar ◽  
Computing Environment ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
The Impact ◽  
Bench Model

Abstract The paper presents the results of the analysis of the striker shape impact on the shape of the mechanical elastic wave generated in the Hopkinson bar. The influence of the tensometer amplifier bandwidth on the stress-strain characteristics obtained in this method was analyzed too. For the purposes of analyzing under the computing environment ABAQUS / Explicit the test bench model was created, and then the analysis of the process of dynamic deformation of the specimen with specific mechanical parameters was carried out. Based on those tests, it was found that the geometry of the end of the striker has an effect on the form of the loading wave and the spectral width of the signal of that wave. Reduction of the striker end diameter reduces unwanted oscillations, however, adversely affects the time of strain rate stabilization. It was determined for the assumed test bench configuration that a tensometric measurement system with a bandwidth equal to 50 kHz is sufficient

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