scholarly journals Measurement of the Shear Properties of Extruded Polystyrene Foam by In-Plane Shear and Asymmetric Four-Point Bending Tests

Polymers ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 47 ◽  
Author(s):  
Hiroshi Yoshihara ◽  
Makoto Maruta
Keyword(s):  
Shear Strength ◽  
Shear Modulus ◽  
Shear Test ◽  
Bending Test ◽  
Polystyrene Foam ◽  
Plane Shear ◽  
Bending Tests ◽  
Four Point Bending ◽  
Four Point Bending Test ◽  
Extruded Polystyrene Foam

The shear modulus and shear strength of extruded polystyrene foam were obtained by the in-plane shear and asymmetric four-point bending tests. In addition, the test data were numerically analysed, and the effectiveness of these tests was examined. The numerical and experimental results suggest that the shear modulus and shear strength obtained from the in-plane shear test are significantly smaller than those obtained from the asymmetric four-point bending test because the influence of the stress concentration was less significant. Although the in-plane shear test is standardised in ASTM C273/C273M-11, it is considerable to adopt the asymmetric four-point bending test as another candidate for obtaining the shear properties of extruded polystyrene foam.

In-plane shear strength of paper measured by asymmetric four-point bending test

Holzforschung ◽  
2015 ◽  
Vol 69 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Hiroshi Yoshihara ◽  
Masahiro Yoshinobu
Keyword(s):  
Shear Strength ◽  
Principal Stress ◽  
Filter Paper ◽  
Bending Test ◽  
Medium Density ◽  
Medium Density Fibreboard ◽  
Plane Shear ◽  
Four Point Bending ◽  
Paper Filter ◽  
Four Point Bending Test

Abstract The in-plane shear strengths (IPSS) of copy paper, filter paper, and sack paper were obtained from an asymmetric four-point bending (AFPB) test. Rectangular tabs of medium-density fibreboard (MDF) were bonded to the paper specimen. The length of the clearance between the tabs was varied, and the influence of the clearance on the IPSS value was investigated. The IPSS obtained from the AFPB test was compared with that obtained from a 35° off-axis tension (OAT) test, which was proposed in a previous study. The IPSS values obtained from the AFPB tests on the copy paper and sack paper were significantly lower than those obtained from the 35° OAT tests because of the localised buckling caused by the negative principal stress. In contrast, the IPSS values obtained from the AFPB and OAT tests on the filter paper were in agreement when the clearance length was >5 mm because the buckling effect was excluded.

scholarly journals Four-Point Bending Tests to Study the So-Called Plasticity Effect on the Residual Stress Results Determined by the Hole-Drilling and Ring-Core Methods

2014 ◽  
Vol 996 ◽  
pp. 319-324
Author(s):  
David von Mirbach
Keyword(s):  
Residual Stress ◽  
Bending Test ◽  
Hole Drilling ◽  
Test Machine ◽  
Bending Tests ◽  
Hole Drilling Method ◽  
Four Point Bending ◽  
Drilling Method ◽  
Four Point Bending Test ◽  
Ring Core

The hole-drilling method (HDM) and ring core method (RCM) are limited to low residual stresses under 60% of the yield stress. This issue will experimentally analyze the method of adaptive calculation function, presented by the author on the ICRS9. With a four-point-bending test machine, a defined stress can be triggered between the middle bending. In this defined loading area, the strains in two load cases with the HDM and the RCM configuration were measured. With these measured strains the residual stress calculation will be analysed.

Analysis of iron aluminide coated beams under creep conditions in high-temperature four-point bending tests

2018 ◽  
Vol 53 (4) ◽  
pp. 255-265 ◽  
Author(s):  
Joachim Nordmann ◽  
Philipp Thiem ◽  
Nuria Cinca ◽  
Konstantin Naumenko ◽  
Manja Krüger
Keyword(s):  
High Temperature ◽  
Creep Behaviour ◽  
Substrate Material ◽  
Iron Aluminide ◽  
Bending Test ◽  
Bending Tests ◽  
Four Point Bending ◽  
Wear And Corrosion ◽  
Four Point Bending Test ◽  
Wear And Corrosion Resistance

Recent research is focused on the possibility to coat a metallic alloy with intermetallics or ceramics to improve wear and corrosion resistance, as well as creep behaviour at high temperatures, next to other properties of the alloy. Nowadays, this gains importance due to stricter environment guidelines. Here, we present a model to describe a non-symmetric compound in a high-temperature four-point bending test, performed at [Formula: see text]. The substrate material is an aluminium alloy AlSi10MgT6, and the coating material is the iron aluminide Fe24Al0.6Nb. Up next, a layer-wise theory is introduced to calculate the forces between substrate and coating. Furthermore, required material parameters are identified, and a new procedure to determine Young’s modulus of a coating is presented. Finally, simulation results are compared to experimental data, illustrating that the presented model is able to describe the material behaviour accurately.

Failure mechanisms in three and four point short beam bending tests of unidirectional glass/epoxy

1992 ◽  
Vol 27 (4) ◽  
pp. 235-243 ◽  
Author(s):  
W C Cui ◽  
M R Wisnom ◽  
M Jones
Keyword(s):  
Shear Stress ◽  
Shear Strength ◽  
Shear Failure ◽  
Beam Theory ◽  
Interlaminar Shear Strength ◽  
Bending Test ◽  
Bending Tests ◽  
Four Point Bending ◽  
Short Beam ◽  
Interlaminar Shear

Three and four point bending tests are compared both analytically and experimentally. In all the three point bending tests, damage was observed under the loading roller in addition to the interlaminar shear failure, while in the four point bending tests, only interlaminar shear failure was observed. Therefore, this four point bending test is valid for measuring the interlaminar shear strength. From the finite element analysis, it is found that the roller diameter is a critical parameter in determining the stress concentrations in short beam tests. In order to avoid damage under the roller and thus to make the short beam test a valid means for measuring the interlaminar shear strength, the appropriate roller diameters should be chosen. The damage under the loading roller in the three point bending test basically reduces the effective specimen thickness and thus this test underestimates the interlaminar shear strength. The interlaminar shear cracks in the short beam tests were found to be randomly distributed in a region between 30 percent and 70 percent through the thickness from the top surface. This is due to the non-linear shear response which means that the shear stress distribution is more uniform near the middle of the section. Also the maximum value of the shear stress is lower than the maximum value given by beam theory. A non-linear shear correction factor is suggested to account for this effect and for the glass/epoxy composite tested here, the actual interlaminar shear strength is only about 83 percent of the apparent value from classical beam theory. The interlaminar shear crack does not occur at the location of maximum shear stress. This may be because there is insufficient energy to propagate a crack at this location.

Method of Measuring the Shear Strength of Wood by the Asymmetric Four-Point Bending Test Using a Notched Beam Specimen

2003 ◽  
Vol 31 (4) ◽  
pp. 11400 ◽  
Author(s):  
DR Petersen ◽  
RE Link ◽  
H Yoshihara ◽  
O Ohhata
Keyword(s):  
Shear Strength ◽  
Bending Test ◽  
Beam Specimen ◽  
Four Point Bending ◽  
Four Point Bending Test

Coupled Nanoscratch and 4-Point Bending Evaluations of Adhesion in SiCN/Cu/Ta/TaN/SiO2/Si Stacked Layers

2008 ◽  
Vol 1086 ◽  
Author(s):  
Kouji Yoneda ◽  
Satoshi Shimizu ◽  
Nobuo Kojima ◽  
Chikai Sato ◽  
Jiping Ye
Keyword(s):  
Thin Film ◽  
Plastic Deformation ◽  
Small Area ◽  
Bending Test ◽  
Adhesion Properties ◽  
Bending Tests ◽  
Four Point Bending ◽  
Quantitative Measurements ◽  
Similarities And Differences ◽  
Four Point Bending Test

AbstractNanoscratch test used for small area measurements and four-point bending test applied for quantitative measurements were coupled to evaluate the adhesive strengths of SiCN/Cu/Ta,/TaN/SiO2/Si stacked layers. The similarities and differences of the two methods concerning adhesion, position of the delamination interface, and plastic deformation of the delaminated film were estimated. It was found that the nanoscratch test gave similar adhesion properties when the delamination interface was the same as that formed by the four-point bending test. The four-point bending test displayed clearer results compared to the nanoscratch test because energy for delamination was not used in plastic deformation and the crack could propagate further. These results suggest that coupling the nanoscratch and four-point bending tests is powerful way to estimate and understand adhesion of thin film materials.

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