Flow Stress and Fracture Toughness Behavior of AA5083 Under Quasi-Static Loading

2022 ◽  
pp. 11-15
Author(s):  
Anoop Kumar Pandouria ◽  
Sanjay Kumar ◽  
Purnashis Chakraborty ◽  
Kuldeep Yadav ◽  
Amit Kumar ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Flow Stress ◽  
Static Loading

Microstructural and fractographic characterization of B4C-Al cermets tested under dynamic and static loading

1989 ◽  
Vol 47 ◽  
pp. 562-563
Author(s):  
Gyeung Ho Kim ◽  
Mehmet Sarikaya ◽  
D. L. Milius ◽  
I. A. Aksay
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Static Loading ◽  
Carbon Deposition ◽  
Full Density ◽  
Unique Combination ◽  
Strong Component ◽  
Reaction Products

Cermets are designed to optimize the mechanical properties of ceramics (hard and strong component) and metals (ductile and tough component) into one system. However, the processing of such systems is a problem in obtaining fully dense composite without deleterious reaction products. In the lightweight (2.65 g/cc) B4C-Al cermet, many of the processing problems have been circumvented. It is now possible to process fully dense B4C-Al cermet with tailored microstructures and achieve unique combination of mechanical properties (fracture strength of over 600 MPa and fracture toughness of 12 MPa-m1/2). In this paper, microstructure and fractography of B4C-Al cermets, tested under dynamic and static loading conditions, are described.The cermet is prepared by infiltration of Al at 1150°C into partially sintered B4C compact under vacuum to full density. Fracture surface replicas were prepared by using cellulose acetate and thin-film carbon deposition. Samples were observed with a Philips 3000 at 100 kV.

Modified Equation to Predict Leak/Rupture Criteria for Axially Through-Wall Notched X80 and X100 Linepipes Having Higher Charpy Energy

2004 ◽  
Author(s):  
Shinobu Kawaguchi ◽  
Naoto Hagiwara ◽  
Mitsuru Ohata ◽  
Masao Toyoda
Keyword(s):  
Fracture Toughness ◽  
Flow Stress ◽  
Pipe Material ◽  
Test Results ◽  
Absorbed Energy ◽  
Bending Tests ◽  
Full Scale Tests ◽  
Hoop Stresses ◽  
The Relationship ◽  
Modified Equation

A method of predicting the leak/rupture criteria for API 5L X80 and X100 linepipes was evaluated, based on the results of hydrostatic full-scale tests for X60, X65, X80 and X100 linepipes with an axially through-wall (TW) notch. The TW notch test results clarified the leak/rupture criteria, that is, the relationship between the initial notch lengths and the maximum hoop stresses during the TW notch tests. The obtained leak/rupture criteria were then compared to the prediction of the Charpy V-notch (CVN) absorbed energy-based equation, which has been proposed by Kiefner et al. The comparison revealed that the CVN-based equation was not applicable to the pipes having a CVN energy (Cv) greater than 130 J and flow stress greater than X65. In order to predict the leak/rupture criteria for these linepipes, the static absorbed energy for ductile cracking, (Cvs)i, was introduced as representing the fracture toughness of a pipe material. The (Cvs)i value was determined from the microscopic observation of the cut and buffed Charpy V-notch specimens after static 3-point bending tests. The CVN energy in the original CVN-based equation was replaced by an equivalent CVN energy, (Cv)eq’ which was defined as follows: (Cv)eq = 4.5 (Cvs)i. The leak/rupture criteria for the X80 and X100 linepipes with higher CVN energies were reasonably predicted by the modified equation using the (Cvs)i value.

FRACTURE BEHAVIOR OF Zr-BASED BULK METALLIC GLASS UNDER IMPACT LOADING

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4359-4364 ◽  
Author(s):  
HYUNG-SEOP SHIN ◽  
KI-HYUN KIM ◽  
SANG-YEOB OH
Keyword(s):  
Fracture Toughness ◽  
Crack Initiation ◽  
Fracture Energy ◽  
Impact Loading ◽  
Static Loading ◽  
Fracture Behavior ◽  
Loading Rate ◽  
Shear Bands ◽  
Maximum Load ◽  
Cu Alloy

The fracture behavior of a Zr -based bulk amorphous metal under impact loading using subsize V-shaped Charpy specimens was investigated. Influences of loading rate on the fracture behavior of amorphous Zr - Al - Ni - Cu alloy were examined. As a result, the maximum load and absorbed fracture energy under impact loading were lower than those under quasi-static loading. A large part of the absorbed fracture energy in the Zr -based BMG was consumed in the process for crack initiation and not for crack propagation. In addition, fractographic characteristics of BMGs, especially the initiation and development of shear bands at the notch tip were investigated. Fractured surfaces under impact loading are smoother than those under quasi-static loading. The absorbed fracture energy appeared differently depending on the appearance of the shear bands developed. It can be found that the fracture energy and fracture toughness of Zr -based BMG are closely related with the extent of shear bands developed during fracture.

Practical Evaluation of the Strain Rate and Temperature Effects on Fracture Toughness of Steels

2015 ◽  
Author(s):  
Koji Gotoh
Keyword(s):  
Fracture Toughness ◽  
Strain Rate ◽  
Static Loading ◽  
Temperature Effects ◽  
Loading Condition ◽  
Temperature Shift ◽  
Evaluation Procedure ◽  
Practical Evaluation ◽  
Temperature Parameter ◽  
Properties Of Materials

Overview of the quantitative evaluation procedure of strain rate and temperature effects on fracture toughness proposed by the authors is introduced. Important concept of former researches is that the fracture toughness is a function of the strain rate-temperature parameter (R), which enables to unify both strain rate and temperature effects for the mechanical properties of materials. Using this knowledge, the equivalent temperature shift values at arbitrary strain rate from static loading condition are proposed.

Theoretical and Experimental Crushing Analysis of Metal Square Honeycombs Under Quasi-Static Loading

2010 ◽  
Author(s):  
M. Zarei Mahmoudabadi ◽  
M. Sadighi ◽  
A. Eyvazian
Keyword(s):  
Flow Stress ◽  
Static Loading ◽  
Experimental Tests ◽  
High Energy ◽  
Geometrical Parameters ◽  
External Work ◽  
Modified Model ◽  
Curvature Effects ◽  
The Mean ◽  
Honeycomb Material

Honeycomb cellular structures, due to their light weight and high energy absorbing, have been used extensively as energy absorbers or cushions to resist external loads. In this paper, the mean crushing stress and the wavelength of the folding mode, as two important parameters in the study of metal square honeycomb crushing under quasi-static loading have been investigated theoretically and experimentally. Firstly, by considering the true cylindrical curvature effects and the flow stress in the folding mode of the honeycomb material, the Wierzbicki’s model in the study of metal hexagonal honeycomb crushing under quasi-static loading is modified. This modification is performed by rewriting the internal energy terms and the external work in the energy method through the basic element folding by considering the true cylindrical curvature effects and the flow stress of the honeycomb material. Comparison of the results obtained by this modified model and Wierzbicki’s model with the experimental data shows better prediction by the model presented in this paper. Subsequently, this modified model has been extended to the study of metal square honeycombs crushing under quasi-static loading and the mean crushing stress and the wavelength of the folding mode of these structures have been predicted. This analytical model predicts the mean crushing stress of the metal square honeycomb as a function of both the geometrical parameters and its material, while the predicted wavelength of the folding mode is just a function of the geometrical parameters. Finally, the experimental tests have been performed to verify the preciseness of this theoretical model.

Fracture mechanics in design and service: ‘living with defects’ - Concluding remarks

1981 ◽  
Vol 299 (1446) ◽  
pp. 237-239
Keyword(s):  
Fracture Toughness ◽  
Plastic Deformation ◽  
Fracture Mechanics ◽  
Static Loading ◽  
Laboratory Tests ◽  
Stress System ◽  
Unstable Fracture ◽  
Reliable Tool ◽  
System A ◽  
Original Objective

The original objective of this meeting was to assess how fracture mechanics is now being used in practice, both in design and service, in different industries, and the extent to which it is now established as a reliable tool. It was hoped to bring together engineers and scientists with experience in different applications of fracture mechanics. My own impressions of some of the important conclusions that have emerged from this meeting are as follows. 1. The simple concept of a constant fracture toughness controlling unstable fracture under nearly l.e.f.m. and quasi-static loading conditions seems to work remarkably well for a variety of materials, including alloys, plastics and composites (see Professor Williams’s paper). But when plastic deformation becomes significant, there are complications, in particular the effects of triaxiality of the stress system, a point stressed by Professor Burdekin, and also of high rates of strain, which must be taken into account in applying toughness values obtained from laboratory tests to actual structures in service.

Large Dataset Assessment of the Upper Shelf Master Curve Model

2017 ◽  
Author(s):  
Mark Kirk ◽  
Marjorie Erickson ◽  
Richard Link
Keyword(s):  
Fracture Toughness ◽  
Flow Stress ◽  
Temperature Dependence ◽  
Ferritic Steel ◽  
High Fracture Toughness ◽  
High Fracture ◽  
Large Dataset ◽  
Scalar Multiple ◽  
Proposed Model ◽  
Curve Model

In 2006, EricksonKirk and EricksonKirk proposed a model describing a temperature dependence for upper shelf fracture toughness (JIc), based on the Zerilli-Armstrong (ZA) temperature dependence of the flow stress, that was common to the large number of ferritic steel datasets studied. The equation describing the temperature dependence of JIc was found to be a simple scalar multiple of the temperature dependence predicted by ZA for flow stress. Since that time a large dataset has been developed containing many experimental measurements of JIc for the purpose assessing and refining the previously proposed model. The new data, reported herein, validates the previously proposed model of JIc temperature dependence but suggests that revisions of the previously proposed model of JIc uncertainty are needed to ensure the applicability of the model to both low and high fracture toughness steels.

Effect of Resin Layer Thickness on Mode II Delamination Growth Property of CFRTP Laminates under Static Loadings

2019 ◽  
Vol 827 ◽  
pp. 446-451
Author(s):  
Kazuto Tanaka ◽  
Kosuke Ishida ◽  
Keisuke Takemoto ◽  
Tsutao Katayama
Keyword(s):  
Fracture Toughness ◽  
Static Loading ◽  
Middle Layer ◽  
Mode Ii ◽  
Thermoplastic Resin ◽  
Growth Property ◽  
Cfrp Laminates ◽  
Delamination Growth ◽  
Resin Layer ◽  
Reinforced Thermoplastics

Carbon Fibre Reinforced Thermoplastics (CFRTP) are expected to be used in various fields for the point of their superior mechanical properties. CFRP laminates with continuous fibres tend to be damaged by microcracks in the layer and interlaminar delamination. Especially, it is necessary to evaluate the mode II delamination growth property, which is correlated with compression after impact (CAI) strength. It is reported that CF/Epoxy laminates with a thicker interlaminar resin layer show higher toughness. By applying an extra thick interlaminar resin layer to CFRTP in which thermoplastic resin with relatively higher fracture toughness is used for the matrix, CFRTP with higher interlaminar fracture toughness can be developed. In this study, the mode II delamination growth property of CFRTP laminates under static loading was evaluated for the specimens with various layer thicknesses of polyamide (PA) resin in the middle layer of the laminates. Their moldability and damage propagation properties were evaluated by three-point bending tests and end notched flexure (ENF) tests. CF/PA laminated composites with a thicker PA layer showed superior mode II delamination growth property under static loading since they had more ductile fracture due to a thicker PA layer.

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