The Effect of Specimen Thickness on the Tearing Energy of a Gum Vulcanizate

1989 ◽  
Vol 62 (5) ◽  
pp. 850-862 ◽  
Author(s):  
Kenneth A. Mazich ◽  
K. N. Morman ◽  
F. G. Oblinger ◽  
T. Y. Fan ◽  
P. C. Killgoar
Keyword(s):  
Finite Element ◽  
Laboratory Experiments ◽  
Pure Shear ◽  
Thickness Effect ◽  
Specimen Thickness ◽  
J Integral ◽  
Shear Specimen ◽  
Standard Specimens ◽  
Finite Element Calculations ◽  
Tearing Energy

Abstract We have examined the effect of thickness on the critical tearing energy of a simple gum vulcanizate of SBR in pure shear. Laboratory experiments and finite-element calculations agree that the tearing energy that is measured with a pure-shear specimen increases with the thickness of the specimen. Laboratory measurements indicate that the deformation for crack growth in a pure-shear specimen increases with the thickness of the specimen. Finite-element calculations show that the energy available for release at a given deformation also increases with thickness in the range from t=1.4 mm to t=14 mm. Experiments show that the crtical tearing energy varies linearly with thickness in the range t=0.7 mm to t=2.7 mm. The effect of thickness on the tearing energy was also studied by calculating the J-integral at various points of the crack through the thickness of the pure-shear specimen. In general, the J-integral calculated at the surface of the specimen can be higher than the J-integral calculated at the center of the specimen for specimens that are sufficiently thick. The thickness effect measured in this work suggests that the “critical tearing energy” obtained from standard laboratory specimens may not be a true material property. For this reason, critical tearing energy that is measured on standard specimens may not be generally applied to predict failure in arbitrary elastomeric components.

Assessment of the Engineering Approach for the Evaluation of C-Shaped Specimens

1990 ◽  
Vol 112 (4) ◽  
pp. 353-366 ◽  
Author(s):  
J. M. Goan ◽  
M. A. Sutton ◽  
Y. J. Chao
Keyword(s):  
Finite Element ◽  
Plane Stress ◽  
Limit Load ◽  
J Integral ◽  
Baseline Study ◽  
Engineering Approach ◽  
Stress Problem ◽  
Standard Specimens ◽  
Finite Element Calculations ◽  
Plane Stress Problem

A baseline study has been carried out to assess the accuracy of the engineering approach for J-integral determination when applied to various standard specimens. Detailed finite element calculations were used to assess the accuracy of this approach. Although certain discrepancies were found when comparing the approximated functions obtained in this work to those in previous work, the error trends are similar and consistent throughout the analysis. Then, the engineering approach outlined in the baseline study is applied to the 2-D plane stress problem of a C-shaped specimen subjected to tension. Derivation of limit-load, fully plastic solutions and elastic-plastic estimation formulas are given in detail. Detailed comparisons between results from estimation solutions and finite element calculations are presented.

Study of Constraint Issues in Elasto-Plastic Fracture Analysis Using Experimental and Finite Element Simulation

2017 ◽  
Author(s):  
Md Ibrahim Kittur ◽  
Krishnaraja G. Kodancha ◽  
C. R. Rajashekar
Keyword(s):  
Finite Element ◽  
Mild Steel ◽  
Compact Tension ◽  
Specimen Thickness ◽  
J Integral ◽  
Crack Tip Opening Displacement ◽  
Opening Displacement ◽  
3D Fea ◽  
The Comparative Study ◽  
Crack Tip Opening

In this investigation, the variation of J-integral considering Compact Tension (CT) specimen geometry varying a/W and σ using 2D and 3D elasto-plastic Finite Element (FE) analysis have been studied. Further, the investigation has been done to examine the relationship between the J and δ for varied a/W and σ. The plane stress and plane strain elasto-plastic FE analyses have been conducted on the CT specimen with a/W = 0.45–0.65 to extract the J and Crack-tip Opening Displacement (CTOD) values for mild steel. The comparative study of the variation of dn with a/W of mild steel with earlier results of IF steel is carried out. The study clearly infers the effect of yield stress on the variation of the magnitude of dn with reference to a/W ratio. The present analysis infers that while converting the magnitude of the CTOD to J one needs to carefully evaluate the value of dn depending on the material rather than considering it to be unity. Further, the study was extended to experimental and 3D FEA wherein J-integral and CTOD were estimated using the CT specimen. Experimental results reveal that the crack length, the specimen thickness, and the loading configuration have an effect on the fracture toughness measurements. The error analysis between the results obtained by 3D FEA and experimentation were conducted and found to be within limits.

Arcan-Richard Specimens: Is there a Pure Shear Mode?

2010 ◽  
Vol 452-453 ◽  
pp. 345-348
Author(s):  
Stanislav Seitl ◽  
Pavel Hutař ◽  
Alfonso Fernández Canteli
Keyword(s):  
Pure Shear ◽  
Shear Mode ◽  
Bend Specimen ◽  
Mixed Mode Loading ◽  
Tension Specimen ◽  
Stress Mode ◽  
Standard Specimens ◽  
Finite Element Calculations ◽  
Point Bend ◽  
Constraint Level

Traditionally, applications of fracture mechanics have been mainly focused on cracks growing under the opening or mode I mechanism (three point bend specimen, middle tension specimen, crack tension specimen, etc.). When investigating instability under mixed mode loading conditions, three different alternatives can be envisaged consisting of: a) machining a hole in standard specimens, b) creating a crack oriented under a given angle, and c) using non-standard Arcan-Richard specimens. In this work, finite element calculations are performed to analyze the initial values of the fracture parameters in Arcan-Richard specimens. First, the influence of the normal stress mode to the shear stress mode ratio is analyzed, then the effect of the constraint level is discussed, and finally, the initial propagation angle of the daughter crack is derived.

Thickness Influence on the Creep Response of DD6 Ni-Based Single-Crystal Superalloy

2016 ◽  
Vol 35 (9) ◽  
pp. 871-880 ◽  
Author(s):  
Zhixun Wen ◽  
Haiqing Pei ◽  
Dongfan Li ◽  
Zhufeng Yue ◽  
Jingyun Gao
Keyword(s):  
Single Crystal ◽  
Oxide Thickness ◽  
Single Crystal Superalloy ◽  
Thickness Effect ◽  
Specimen Thickness ◽  
Thin Wall ◽  
Creep Life ◽  
Creep Response ◽  
Standard Specimens ◽  
Lower Temperature

AbstractThe effect of specimen thickness on the creep response of Ni-based single-crystal superalloy DD6 was investigated. With the thickness of 0.3 mm, 0.6 mm and 1.2 mm, a series of thin-wall specimens were tested in this paper respectively at 760℃, 980℃ and 1,100℃. Under the conditions of lower temperatures and higher stresses, the creep life of thin-wall specimens increases with the increase of δ, but it is almost equal under higher temperatures and lower stresses conditions. Compared with the standard specimens, an obvious reduction (about 60%) of creep life of the thin-wall specimens was found at 760℃, whereas it is almost the same at 980℃ and 1,100℃. Therefore, obvious thickness effect is prone to lower temperature and higher stress. The thickness effect is a comprehensive effect, which is caused by fracture mode, the degree of necking, the shape and quantity of creep cavities, oxide thickness, etc. Under each condition, an increased thickness resulted in increased creep strain to rupture.

Finite Element Analyses for Thickness Effects on J-Integral Testing using Non-Standard Testing Specimens

2004 ◽  
Vol 261-263 ◽  
pp. 693-698
Author(s):  
J.S. Kim ◽  
Young Jin Kim ◽  
S.M. Cho
Keyword(s):  
Fracture Toughness ◽  
Finite Element ◽  
Three Dimensional ◽  
Specimen Thickness ◽  
J Integral ◽  
Finite Element Analyses ◽  
Single Edge ◽  
Fracture Toughness Testing ◽  
Standard Testing ◽  
Toughness Testing

This paper compiles solutions of plastic η factors for standard and non-standard fracture toughness testing specimens, via detailed three-dimensional (3-D) finite element (FE) analyses. Fracture toughness testing specimens include a middle cracked tension (M(T)) specimen, SE(B), single-edge cracked bar in tension (SE(T)) and C(T) specimen. The ligament-to-thickness ratio of the specimen is systematically varied. It is found that the use of the CMOD overall provides more robust experimental estimation than that of the LLD, for all cases considered in the present work. Moreover, the estimation based on the load- CMOD record is shown to be insensitive to the specimen thickness, and thus can be used for testing a specimen with any thickness.

Validating the Mechanical Nature of the Test Speicmen Thickness Effect on Fracture Toughness in the Transition Temperature Region

2013 ◽  
Author(s):  
Toshiyuki Meshii ◽  
Kai Lu ◽  
Ryota Takamura
Keyword(s):  
Fracture Toughness ◽  
Transition Temperature ◽  
Temperature Region ◽  
Standard Test ◽  
Thickness Effect ◽  
Specimen Thickness ◽  
Weakest Link ◽  
Standard Specimens ◽  
Out Of Plane ◽  
Crack Tip Constraint

This paper considered the test specimen thickness (TST) effect on the fracture toughness of a material Jc, in the transition temperature region, for 3PB (i.e., SE(B) for ASTM standard) specimens. Fracture toughness tests and elastic-plastic finite element analyses (FEA) with non-standard test specimens, on the point that the specimen thickness to width to ratio B/W was varied in the range of 0.25 to 1.5, were conducted. Based on these tests and FEA results, it was demonstrated that Jc showed tendency to saturate to some lower bound for B/W = 1.5. This tendency was similar with that predicted by our previous work, which assumed the TST effect on Jc as an out-of-plane crack-tip constraint issue. Because the TST effect on Jc (such as Jc ∝ B(−1/2)) together with Jc’s bounding nature for large B could not be predicted by the weakest link model but out-of-plane constraint assumption worked, it was concluded that the TST effect is mainly mechanical in nature.

scholarly journals Pre-Clinical Testing of Hip Prosthetic Designs: A Comparison of Finite Element Calculations and Laboratory Tests

1993 ◽  
Vol 207 (3) ◽  
pp. 149-154 ◽  
Author(s):  
N J J Verdonschot ◽  
R Huiskes ◽  
M A R Freeman
Keyword(s):  
Finite Element ◽  
Laboratory Tests ◽  
Laboratory Experiments ◽  
Load Transfer ◽  
Three Dimensional ◽  
Fe Analysis ◽  
Design Evaluation ◽  
Clinical Testing ◽  
Hip Prostheses ◽  
Finite Element Calculations

To investigate the accuracy of finite element (FE) models for pre-clinical testing of unbonded hip prostheses, relative to aspects of load transfer and micromobility, two previously published laboratory experiments were simulated, using three-dimensional FE models. It was found for the load-transfer analyses that the experiment and the FE study revealed results that were very similar. The trends in the mobility experiments were also reproduced in the FE simulations, although quantitative differences were found. It is concluded that FE analysis can effectively be used for design evaluation of hip prostheses before prototypes are made.

Analysis of Fatigue Life of SPR (Self-Piercing Riveting) Jointed Various Specimens Using FEM

2008 ◽  
Vol 580-582 ◽  
pp. 617-620 ◽  
Author(s):  
Bok Kyu Lim
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Fatigue Behavior ◽  
Pure Shear ◽  
Automotive Application ◽  
Finite Element Models ◽  
Tensile Shear ◽  
Element Analysis ◽  
Shear Specimen ◽  
Cross Tension

Self-Piercing Riveting(SPR) is becoming an important joining technique for various material sheets and shapes, of automotive application. Fatigue behavior of SPR connections needs to be investigated experimentally and numerically to predict SPR fatigue lives. The simulations of various SPR specimens (Coach-Peel specimen, Cross-Tension specimen, Tensile-Shear specimen, Pure-Shear specimen) are performed to predict the fatigue life of SPR connections under different shape combinations. Finite element models of various SPR specimens are developed using a FEMFAT SPOT SPR pre-processor. The fatigue lives of SPR specimens are predicted using a FEMFAT 4.4e based on the linear finite element analysis.

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