FURTHER EVALUATION OF PROPOSED BIAXIAL STRESS TEST SPECIMEN FOR COMPOSITE MATERIALS

1980 ◽  
pp. 885-899 ◽  
Author(s):  
Richard H. MARLOFF ◽  
Stephen E. GABRIELSE
Keyword(s):  
Composite Materials ◽  
Test Specimen ◽  
Stress Test ◽  
Biaxial Stress

Tensile and Wear Behaviour of Aluminium Alloy LM6 Reinforced with Magnesium and Copper

2019 ◽  
Vol 16 (2) ◽  
pp. 725-728
Author(s):  
Prabhu G. Rubesh ◽  
P. Jayaseelan ◽  
Mona Sahu
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Composite Materials ◽  
Metal Matrix ◽  
Test Specimen ◽  
Wear Behavior ◽  
Stir Casting ◽  
Wear Behaviour ◽  
Casting Technique ◽  
Reinforcing Material

The aim of this research is to fabricate aluminum based metal matrix composite and reviewing its tensile strength and wear behavior of produced test specimen. In this work an attempt is made to develop an aluminium based MMCs with reinforcing material and stir casting technique has been used to achieve this. Aluminum alloy (LM6) and Magnesium (Mg), Copper (Cu) was chosen as metal matrix and composite materials respectively, tensile and wear experiments has been conducted by varying the composition of Cu (0.150%, 0.175% and 2%) while keeping Mg (0.150%) as constant. The result shows that the increase in addition of copper increases the tensile strength and wears resistance and decreases the percentage of elongation.

Known Residual Stress Specimens Using Opposed Indentation

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Pierluigi Pagliaro ◽  
Michael B. Prime ◽  
Bjørn Clausen ◽  
Manuel L. Lovato ◽  
Bernardo Zuccarello
Keyword(s):  
Residual Stress ◽  
Stress Measurement ◽  
Stress Test ◽  
Biaxial Stress ◽  
Contour Method ◽  
Cyclic Behavior ◽  
Hardening Law ◽  
Biaxial Stress State ◽  
Complicated Geometries ◽  
Hoop Stresses

In order to test new theories for residual stress measurement or to test the effects of residual stress on fatigue, fracture, and stress corrosion cracking, a known stress test specimen was designed and then fabricated, modeled, and experimentally validated. To provide a unique biaxial stress state, a 60 mm diameter 10 mm thick disk of 316L stainless steel was plastically compressed through the thickness with an opposing 15 mm diameter hard steel indenters in the center of the disk. For validation, the stresses in the specimen were first mapped using time-of-flight neutron diffraction and Rietveld full pattern analysis. Next, the hoop stresses were mapped on a cross section of two disks using the contour method. The contour results were very repeatable and agreed well with the neutron results. The indentation process was modeled using the finite element method. Because of a significant Bauschinger effect, accurate modeling required testing the cyclic behavior of the steel and then modeling it using a Chaboche-type combined hardening law. The model results agreed very well with the measurements. The duplicate contour measurements demonstrated stress repeatability better than 0.01% of the elastic modulus and allowed discussion of implications of measurements of parts with complicated geometries.

scholarly journals Fatigue tests, self-healing of polymer-matrix composites in unmanned aerial vehicles

2018 ◽  
Vol 48 (1) ◽  
pp. 83-106
Author(s):  
Sławomir Augustyn ◽  
Rafał Kowalski
Keyword(s):  
Composite Materials ◽  
Polymer Matrix Composites ◽  
Stress Test ◽  
Fatigue Tests ◽  
Fiber Reinforced Polymer ◽  
Self Healing ◽  
Matrix Composites ◽  
Four Point Bending ◽  
Reinforced Polymer ◽  
Initial Load

Abstract This publication presented the main issues related to fatigue of polymer composite materials. It was featured a fatigue stress test based on composite sample, made of carbon fiber-reinforced polymer, using the four-point bending method. The test was carried out with the initial load and using positive load cycles. The perspectives of diagnostics and self-healing of composite materials, including intelligent materials, were also presented.

scholarly journals Structural failure criterion for spatially-reinforced carbon-carbon composite materials

2020 ◽  
pp. 48-59
Author(s):  
I. V Magnitsky
Keyword(s):  
Composite Materials ◽  
Yield Stress ◽  
Carbon Composite ◽  
Biaxial Stress ◽  
Failure Behavior ◽  
Model Parameters ◽  
Elastic Model ◽  
Structural Cell ◽  
Carbon Composite Materials ◽  
Suggested Criterion

This paper defines the structural strength criterion for 4DL-reinforced carbon-carbon materials. For this scheme, fiber reinforcement consists of four groups of reinforcing elements, three of them are located in parallel planes with the angles of 120° between them and the fourth one is normal to them. The paper addresses the first failure of the material corresponding to its yield stress, in this point, one of the material components deviates from linear elastic behavior. A composite material is considered to be non-uniform structurally and consists of a matrix and reinforcing elements, rods. Those rods, in their turn, represent a unidirectional composite. To analyze the stress-strain state of individual components of the material, a three-level elastic model is built that uses the analytic approach at the micro level, while at higher levels it uses the finite element method. For numerical calculations, a structural cell of the material is taken. The boundary conditions provide small to negligible influence of the edge effects, thus simulating the behavior of the infinite volume of the material. For the material components, local strength criteria are introduced, where the fields of the criterion quantities are averaged over the volume of the structural cell. The strength surface of the material that corresponds to its first failure is obtained, and the conclusion is made that the suggested criterion provides a reasonable agreement with the available data on the typical carbon-carbon composite characteristics. Based on the calculated dependencies of the material’s yield stress on the load direction, a procedure is suggested to identify the model parameters based on the material failure behavior analysis using standard tensile and compressive tests. Estimated discrepancies between the results calculated using the suggested criterion and those obtained using the limiting stress criterion for biaxial stress states are given. It is shown that the discrepancy may reach tens of percent and in some cases the material strength increases in comparison with that in the uniaxial stress state. The results are subject to verification tests in order to verify the model for advanced spatially reinforced carbon-carbon composite materials.

Optimized Yield Curve Determination Using Bulge Test Combined with Optical Measurement and Material Thickness Compensation

2013 ◽  
Vol 549 ◽  
pp. 389-396 ◽  
Author(s):  
Harald Friebe ◽  
Markus Klein ◽  
Ingo Heinle ◽  
Arnulf Lipp
Keyword(s):  
Stress State ◽  
Flow Curve ◽  
Test Specimen ◽  
Yield Curve ◽  
Optical Measurement ◽  
Biaxial Stress ◽  
Bulge Test ◽  
Forming Process ◽  
Biaxial Stress State ◽  
Curve Determination

Axisymmetric die and binder are typically used in the bulge test, where the test specimen is formed by increasing the level of oil pressure (Fig. 1). With this experimental setup a biaxial stress state is induced at the specimen dome, assuming that it is not influenced by friction. The increasing oil pressure in the region of the top of the dome is recorded and the deformation field measured during the forming process. The optical measurement system determines the coordinates, the deformations and the curvature on the outer surface. Based on the forthcoming ISO 16808 these results are directly used for the calculation of the flow curve. In order to determine the flow curve based on the bulge test, an analytical approach is needed for the computation of the stress state at the top of the dome.

scholarly journals Wear and Water Absorption Behaviour of Banana and Sisal Hybrid Fiber Polymer Composites

2018 ◽  
Vol 7 (3.34) ◽  
pp. 424 ◽  
Author(s):  
Pramod V Badyankal ◽  
Manjunatha T S ◽  
Gurushanth B Veggar
Keyword(s):  
Composite Materials ◽  
Wear Rate ◽  
Water Absorption ◽  
Test Specimen ◽  
Natural Fibers ◽  
Taguchi Technique ◽  
Hybrid Fiber ◽  
Pin On Disc ◽  
Percentage Of Water Absorption ◽  
Process Method

Natural fibers are available naturally from geological, animals and plants. The composite materials can be produced by using these fibers for good properties. In this present work the hybridization of randomly oriented Banana [B] and Sisal [S] of proper composition 20%B 30%S, 30%B 20%S and 25%B 25 %S using 50% Epoxy L-12 resin with the hardener K6 in the 10:1 ratio under cold process method was used. According to ASTM G99 specimens are used to calculate the specific wear rate by pin on disc method and using Taguchi technique. The test specimen with 12 X 12 X 40 mm3 was used to calculate the percentage of water absorption. 

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