scholarly journals Post Impact Tensile and Single Edge Notch Bending Test of Kenaf Hybrid Composite

2019 ◽  
Vol 9 (1) ◽  
pp. 5657-5662
Keyword(s):  
Tensile Test ◽  
Hybrid Composites ◽  
Testing Machine ◽  
Bending Test ◽  
Single Edge ◽  
Single Edge Notch ◽  
Wide Range ◽  
Edge Notch ◽  
Post Impact ◽  
Single Edge Notch Bend

The improvement of elite building items produced using regular assets is expanding around the world due to renewable and ecological issues. Among the wide range of characteristic assets, kenaf plants have been broadly abused in the course of recent years. The aim of this research is to develop long kenaf composites and long kenaf with woven glass reinforced polyester resin composites. Tensile test helps to determine how the material will react to forces being applied in tension. The test that was conducted included Post Impact Tensile test and Single Edge Notch Bend. Tensile test determines strain-stress while single edge notch bend determines the fracture of the specimen. The experiment was conducted using Universal Testing Machine (UTM) to find the mechanical properties. The experiment considered ASTM D3039 for tensile test and ASTM D5045 for single edge notch bending. From there, the damage area of the composites could be predicted. Meanwhile, it showed the best configuration for the newly developed material in impact test. So, these hybrid composites are viable to be extended into a newly developed material for further investigation

scholarly journals Fracture mechanics of hybrid composites with ductile matrix and brittle fibers: Influence of temperature and constraint effect

2018 ◽  
Vol 53 (10) ◽  
pp. 1361-1376 ◽  
Author(s):  
B Vieille ◽  
J-D Gonzalez ◽  
C Bouvet
Keyword(s):  
Tensile Test ◽  
Hybrid Composites ◽  
Glass Fibers ◽  
Moderate Increase ◽  
Single Edge ◽  
Constraint Effect ◽  
Single Edge Notch ◽  
Polyether Ether Ketone ◽  
Edge Notch ◽  
Ether Ketone

The fracture behavior of hybrid carbon and glass fiber woven-ply reinforced polyether ether ketone thermoplastic quasi-isotropic laminates is investigated. Single-edge-notch bending and single-edge-notch tensile tests were conducted at room temperature and at a temperature higher than the glass transition temperature ( Tg) to study the influence of both the constraint effect and the temperature on the strain energy release rate in laminates with ductile polyether ether ketone matrix and brittle fibers. As failure is primarily driven by fibers breakage in tension (single-edge-notch tensile test) and in tension/compression (single-edge-notch bending), it turns out that a temperature increase has very little influence on the mode I critical translaminar fracture toughness KIc though the ductility of polyether ether ketone matrix is exacerbated at T >  Tg. It also appears that the constraint effect has very little influence on KIc as single-edge-notch tensile test and single-edge-notch bending specimens have virtually the same mean value (about 45MPa. [Formula: see text]). Single-edge-notch bending specimens being characterized by a gradual failure, the G-R curves were derived from the computation of the compliance loss and the corresponding gradual crack growth in agreement with the ASTM standard E1820. From the evolution of the G-R curves at high temperature, the highly ductile behavior of the polyether ether ketone matrix at T >  Tg provides a good intrinsic toughness to the material, and the bridging of translaminar crack by the glass fibers at the outer surfaces of laminates contribute to a moderate increase in its extrinsic toughness.

Wide Range Compliance Solutions for Various Fracture Test Specimens Using Crack Mouth Opening Displacement

2017 ◽  
Author(s):  
Claudio Ruggieri ◽  
Rodolfo F. de Souza
Keyword(s):  
Mouth Opening ◽  
Crack Mouth Opening Displacement ◽  
Width Ratio ◽  
Fracture Test ◽  
Single Edge ◽  
Opening Displacement ◽  
Element Analysis ◽  
Single Edge Notch ◽  
Wide Range ◽  
Edge Notch

This work addresses the development of wide range compliance solutions for tensile-loaded and bend specimens based on CMOD. The study covers selected standard and non-standard fracture test specimens, including the compact tension C(T) configuration, the single edge notch tension SE(T) specimen with fixed-grip loading (clamped ends) and the single edge notch bend SE(B) geometry with varying specimen spam over width ratio and loaded under 3-point and 4-point flexural configuration. Very detailed elastic finite element analysis in 2-D setting are conducted on fracture models with varying crack sizes to generate the evolution of load with displacement for those configurations from which the dependence of specimen compliance on crack length, specimen geometry and loading mode is determined. The extensive numerical analyses conducted here provide a larger set of solutions upon which more accurate experimental evaluations of crack size changes in fracture toughness and fatigue crack growth testing can be made.

Warm Pre-Stressing and Leaks in Pipelines

2014 ◽  
Author(s):  
Andrew Cosham ◽  
Phil Hopkins ◽  
David G. Jones ◽  
Julian Barnett
Keyword(s):  
Beneficial Effect ◽  
Pipe Steel ◽  
Theoretical Models ◽  
Manganese Steel ◽  
Single Edge ◽  
Line Pipe ◽  
Single Edge Notch ◽  
Edge Notch ◽  
Line Pipe Steel ◽  
Single Edge Notch Bend

Line pipe steel is a carbon manganese steel. The toughness of line pipe steel undergoes a transition from high toughness (on the upper shelf) to low toughness (on the lower shelf) as the temperature decreases. A fluid will cool significantly as it expands through a leak in a pipeline. This has led to the suggestion that localised cooling of the material surrounding the leak might be sufficient to cool the material down to below the ductile to brittle transition temperature and cause a brittle fracture. Warm pre-stressing occurs when a load is applied to a structure containing a defect and then the temperature of the structure is reduced. Warm pre-stressing causes the defect in the structure to fail at a higher load at the lower temperature than if it had not experienced this prior loading at the previously higher temperature. A programme of single edge notch bend tests has been conducted on behalf of National Grid Carbon to demonstrate the beneficial effect of warm pre-stressing in a line pipe steel. The material tested was a sample of 914.4 mm outside diameter, 19.1 mm wall thickness, Grade API 5L X60 line pipe. Single edge notch bend specimens were subject to the ‘load-cool-fail’ cycle and the ‘load-unload-cool-fail’ cycle. The effect of different levels of stable ductile crack growth during the pre-load was also investigated. Warm pre-stressing is shown to have a beneficial effect. The load at failure in the specimens that had been subject to warm pre-stressing was higher than those that had not been subject to warm pre-stressing, and, in most cases, it was higher than the pre-load. The fracture toughness (in terms of the stress intensity factor) of the specimens that had been subject to warm pre-stressing was 1.4 to 1.7 times higher than that of those that had not been subject to warm pre-stressing. The results of the tests were conservatively predicted using the theoretical models. Also, the results are consistent with previous tests on structural steels. Therefore, localised cooling of the material around a leak in a pipeline is not predicted to result in a failure.

Fracture Toughness Estimation for Pipeline Girth Welds

2002 ◽  
Author(s):  
Henryk G. Pisarski ◽  
Colin M. Wignall
Keyword(s):  
Fracture Toughness ◽  
Weld Metal ◽  
Specimen Geometry ◽  
Single Edge ◽  
Single Edge Notch ◽  
Edge Notch ◽  
Loading Modes ◽  
Girth Welds ◽  
The Relationship ◽  
Single Edge Notch Bend

The relationship between fracture toughness estimated using standard single edge notch bend (SENB), single edge notch tension (SENT) test specimens and fracture toughness associated with a circumferential flaw in a pipe girth weld is explored in terms of constraint using the Q parameter. It is shown that in the elastic-plastic regime, use of standard deeply notched SENB specimens provides a conservative assessment of fracture toughness, for both weld metal and HAZ, because of the high constraint associated with this specimen geometry. Use of specimen geometries and loading modes associated with lower constraint (e.g. SENT and shallowed notched SENB specimens), allow for improved estimates of fracture toughness to be made that are appropriate for the assessment of circumferential flaws in pipe girth welds. Recommendations are given on the specimen designs and notch orientations to be employed when evaluating weld metal and HAZ fracture toughness.

Rotation Corrections in Three-Point Single Edge Notch Bend Specimens

1989 ◽  
Vol 17 (6) ◽  
pp. 381 ◽  
Author(s):  
A Wolfenden ◽  
JE Perez Ipiña ◽  
EL Santarelli
Keyword(s):  
Single Edge ◽  
Single Edge Notch ◽  
Edge Notch ◽  
Single Edge Notch Bend

Integrity of Longitudinal Welds in Pipelines: Bridging Scales

2018 ◽  
Author(s):  
Marion Erdelen-Peppler ◽  
Christoph Kalwa ◽  
Jens Schröder
Keyword(s):  
Circumferential Stress ◽  
Ring Expansion ◽  
Structural Behavior ◽  
Single Edge ◽  
Crack Tip Opening Displacement ◽  
Single Edge Notch ◽  
Wide Range ◽  
Edge Notch ◽  
Longitudinal Welds ◽  
The Impact

Toughness testing of the heat affected zone (HAZ) of longitudinal welds is increasingly often required in pipeline standards and specifications. This includes simple tests such as the Charpy impact test that was designed to serve as quality test as well as enhanced methods including crack tip opening displacement (CTOD) tests that are necessary to conduct an engineering critical assessment (ECA). If occasional low toughness values are observed, the question turns towards assessing the impact of such numbers and how representative they are of the behavior of a pipe in service. The significance of low toughness values measured in laboratory testing can be judged on basis of ring expansion and hydraulic burst tests. The current study summarises an extensive test series to quantify the toughness of submerged arc welds (SAW) obtained by different test methods. The tested pipes cover a wide range of material including medium strength X70 up to high strength X100. Their welds are characterized in terms of fracture toughness properties with single edge notch tension (SENT) and single edge notch bending (SENB) tests. Different constraint levels are obtained within each series by introducing notches of standard depth as well as shallow notches. Structural behavior is characterized with burst tests as well as ring expansion tests containing notches in the longitudinal weld. The experimental results are assessed within dedicated finite element studies. The assessment is conducted for pipes serving as pressure containment, thus having circumferential stress resulting from internal pressure. Based on the results achieved the conclusion can be drawn that the standard route including high constraint CTOD leads to overly conservative results concerning the integrity of longitudinal welds. A better representation of structural behavior is observed in ring expansion tests.

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