scholarly journals Analytical expression for the stress-strain curve of a dual phase material comprising two different strength level phases. Discussion of the results of the multiple X-ray peak method.

1989 ◽  
Vol 55 (520) ◽  
pp. 2488-2494
Author(s):  
Akio TAKIMOTO ◽  
Shinji YOSHINAKA ◽  
Yoshihiro NAKAMICHI
Keyword(s):  
Strain Curve ◽  
Strength Level ◽  
Dual Phase ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
X Ray ◽  
Analytical Expression

Determination of Stress-Strain Curve of Dual Phase Steel by Nanoindentation Technique

2015 ◽  
Vol 658 ◽  
pp. 195-201 ◽  
Author(s):  
Suttirat Punyamueang ◽  
Vitoon Uthaisangsuk
Keyword(s):  
Strain Curve ◽  
High Strength ◽  
Dual Phase ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Dp Steel ◽  
Multiphase Microstructure ◽  
Indentation Tests ◽  
Novel Material ◽  
Parallel Finite Element

The advanced high strength (AHS) steels, for example, dual phase (DP) steels, transformation induced plasticity (TRIP) steels and complex (CP) steels principally exhibit multiphase microstructure features. Thus, mechanical behavior of the constituent phases significantly affects the resulting overall properties of such AHS steels. Novel material characterization techniques on micro- and nano-scale have become greatly more important. In this work, stress-strain response of the DP steel grade 1000 was determined by using the Nanoindentation testing. The DP steel showed the microstructure containing finely distributed martensite islands of about 50% phase fraction in the ferritic matrix. The nano-hardness measurements were firstly performed on each individual phase of the examined steel. In parallel, finite element (FE) simulations of the corresponding nano-indentation tests were carried out. Flow curves of the single ferritic and martensitic phases were defined according to a dislocation based theory. Afterwards, the load and penetration depth curves resulted from the experiments and simulations were compared. By this manner, the proper stress-strain responses of both phases were identified and verified. Finally, the effective stress-strain curve of the investigated DP steel could be determined by using 2D representative volume element (RVE) model.

scholarly journals On the inhomogeneity of plastic deformation in the crystals of an aggregate

1948 ◽  
Vol 193 (1032) ◽  
pp. 89-97 ◽  
Keyword(s):  
Plastic Deformation ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Tensile Deformation ◽  
Strain Curve ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
X Ray

The variation of plastic deformation in aluminium specimens consisting of large crystals has been determined by measuring elongation and hardness at various points after tensile deformation. The deformation varied from grain to grain, and also within each grain the deformation near the boundary was greater or smaller than at the centre according to whether the neighbour was more or less deformed, i. e. there is not necessarily inhibition of slip near grain boundaries. These results were supported by metallographic and X-ray observations. Their importance with respect to the calculation of the stress-strain curve of aggregates from those of single crystals is discussed. It is suggested that a mechanism other than slip operates near the grain boundaries during deformation, and even within the crystals during large extensions.

Numerical Study on the Mechanical Behavior of Aluminum Foam Material Using CT Image

2009 ◽  
Vol 79-82 ◽  
pp. 1297-1300 ◽  
Author(s):  
Hyup Jae Chung ◽  
Kyong Yop Rhee ◽  
Beom Suck Han ◽  
Yong Mun Ryu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Aluminum Foam ◽  
Three Dimensional ◽  
Strain Curve ◽  
Foam Material ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Element Analysis ◽  
X Ray

In this study, finite element analysis was made to predict the tensile and compressive behaviors of aluminum foam material. The predicted tensile and compressive behaviors were compared with those determined from the tensile and compressive tests. X-ray imaging technique was used to determine internal structure of aluminum foam material. That is, X-ray computed tomography (CT) was used to model the porosities of the material. Three-dimensional finite element modeling was made by stacking two-dimensional tomography of aluminum foam material determined from CT images. The stackings of CT images were processed by three-dimensional modeling program. The results showed that the tensile stress-strain curve predicted from the finite element analysis was similar to that determined by the experiment. The simulated compressive stress-strain curve also showed similar tendency with that of experiment up to about 0.4 strain but exhibited a different behavior from the experimental one after 0.4 strain. The discrepancy of compressive stress-strain curves in a high strain range was associated with the contact of aluminum foam walls broken by the large deformation.

scholarly journals Correlation Modeling between Morphology and Compression Behavior of Closed-Cell Al Foams Based on X-Ray Computed Tomography Observations

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1370
Author(s):  
Girolamo Costanza ◽  
Fabio Giudice ◽  
Andrea Sili ◽  
Maria Elisa Tata
Keyword(s):  
Computed Tomography ◽  
Local Level ◽  
Strain Curve ◽  
Equivalent Diameter ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
X Ray ◽  
Closed Cell ◽  
X Ray Computed ◽  
Al Foams

In the last decades, great attention has been focused on the characterization of cellular foams, because of their morphological peculiarities that allow for obtaining effective combinations of structural properties. A predictive analytical model for the compressive behavior of closed-cell Al foams, based on the correlation between the morphology of the cellular structure and its mechanical response, was developed. The cells’ morphology of cylindrical specimens was investigated at different steps of compression by X-ray computed tomography, in order to detect the collapse evolution. The structure, typically inhomogeneous at local level, was represented by developing a global virtual model consisting of homogeneous cells ordered in space, that was fitted on the experimentally detected structure at each deformation step. As a result, the main parameters characterizing the two-dimensional cells morphology (equivalent diameter, circularity), processed by the model, allowed to simulate the whole compression stress–strain curve by enveloping those obtained for each step. The model, fitted on the previous foam, was validated by comparing the simulated stress–strain curve and the corresponding experimental one, detected for similar foams obtained by different powder compositions. The effectiveness in terms of an accurate prediction of the compression response up to the final densification regime has been confirmed.

A modified version of MATLAB application window for predicting the weld bead profile and stress–strain plot of AA5052 CMT weldment using ER4043

SIMULATION ◽  
2021 ◽  
pp. 003754972110315
Author(s):  
B Girinath ◽  
N Siva Shanmugam
Keyword(s):  
Strain Curve ◽  
Weld Bead ◽  
Welding Parameters ◽  
Bead Geometry ◽  
Hybrid Technique ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Weld Bead Geometry ◽  
Inference System ◽  
Engineering Stress

The present study deals with the extended version of our previous research work. In this article, for predicting the entire weld bead geometry and engineering stress–strain curve of the cold metal transfer (CMT) weldment, a MATLAB based application window (second version) is developed with certain modifications. In the first version, for predicting the entire weld bead geometry, apart from weld bead characteristics, x and y coordinates (24 from each) of the extracted points are considered. Finally, in the first version, 53 output values (five for weld bead characteristics and 48 for x and y coordinates) are predicted using both multiple regression analysis (MRA) and adaptive neuro fuzzy inference system (ANFIS) technique to get an idea related to the complete weld bead geometry without performing the actual welding process. The obtained weld bead shapes using both the techniques are compared with the experimentally obtained bead shapes. Based on the results obtained from the first version and the knowledge acquired from literature, the complete shape of weld bead obtained using ANFIS is in good agreement with the experimentally obtained weld bead shape. This motivated us to adopt a hybrid technique known as ANFIS (combined artificial neural network and fuzzy features) alone in this paper for predicting the weld bead shape and engineering stress–strain curve of the welded joint. In the present study, an attempt is made to evaluate the accuracy of the prediction when the number of trials is reduced to half and increasing the number of data points from the macrograph to twice. Complete weld bead geometry and the engineering stress–strain curves were predicted against the input welding parameters (welding current and welding speed), fed by the user in the MATLAB application window. Finally, the entire weld bead geometries were predicted by both the first and the second version are compared and validated with the experimentally obtained weld bead shapes. The similar procedure was followed for predicting the engineering stress–strain curve to compare with experimental outcomes.

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