Thermo-Oxidation Analysis of Structural Adhesives: An Experimental Study

2020 ◽  
Author(s):  
Sharif Alazhary ◽  
Hamid Mohammadi ◽  
Roozbeh Dargazany
Keyword(s):  
Experimental Study ◽  
Testing Machine ◽  
Tensile Tests ◽  
Material Behavior ◽  
Constitutive Behavior ◽  
Tensile Testing Machine ◽  
Model Free ◽  
Structural Applications ◽  
Aging Conditions ◽  
Effects Of Aging

Abstract Cross-linked polymers play an important role in structural applications as adhesives. In this article, we performed an experimental study to understand the effects of high temperature i.e. thermo-oxidative aging on the mechanical behavior of polymers. Subsequently, the constitutive behavior, i.e. stress-strain relation of these adhesives before and after the accelerated aging tests were studied on samples aged at different temperature and different time durations at zero humidity. The aging conditions and periods selected for the tests have been specifically designed to simulate the effects of aging under the working conditions that the materials will be subjected to in their standard applications. The focus of this study is on the investigation of the effects of aging on the polymeric adhesives used in automotive applications. Consequently, four different polymeric adhesives (one silicone-based, two polyurethane-based, and one acrylic type), which are being used extensively in these applications, have been chosen. The quasi-static tensile loading was used on these four adhesives and the changes in the constitutive behavior were measured. The failure tensile tests as well as the cyclic tensile tests were performed in our lab using a Test-Resources tensile testing machine. The temperatures that were used in this work are 60, 80 and 95°C for varying aging periods of 24hrs, 240hrs, and 720hrs. Then, all the data was collected and consequently analyzed, and the resulting behavior was compared to that of the unaged material, showing varying results depending on the material, temperature, and aging period. Different behaviors have been observed after aging. The polymers’ behavior was expanding from no effect to significant damage caused by aging conditions. This work provides the core understanding required for modeling the material behavior during aging and lays down the groundwork for further data-infused model-free approaches.

scholarly journals Research on multidimensional loading device of material mechanical test

2018 ◽  
Vol 207 ◽  
pp. 03012
Author(s):  
Guohua Zhao ◽  
Dan Wang ◽  
Liangbao Liu ◽  
Rui Fanand ◽  
Rukun Mi
Keyword(s):  
Tensile Testing ◽  
Inverse Kinematics ◽  
Parallel Mechanism ◽  
Mechanical Test ◽  
Testing Machine ◽  
Tensile Tests ◽  
Determination Method ◽  
Average Yield ◽  
Tensile Testing Machine ◽  
Loading Device

A multidimensional loading device for the material mechanical test based on Stewart Platform was proposed and manufactured in this paper. A determination method of mechanism parameters toward specific engineering requirements was analysed via inverse kinematics and contact interference boundary condition of mechanism components. A set of optimized mechanism parameters was achieved and then the pose space was obtained. Meanwhile, five repeated quasi-static standard tensile tests were performed on the multidimensional loading device and the standard tensile testing machine, respectively. The average yield strength and ultimate strength of the specimen achieved from the different testers were both merely 1.13%. Results indicated that material mechanical multidimensional loading could be conducted by the parallel mechanism.

Fabrication and Characterization of Micro-Patterned Magnetorheological Elastomeric Structures

2013 ◽  
Author(s):  
Ammar S. Yashaa ◽  
Souran Manoochehri
Keyword(s):  
Size Range ◽  
Testing Machine ◽  
Magnetorheological Fluid ◽  
Tensile Tests ◽  
Tensile Testing Machine ◽  
Latitudinal Patterns ◽  
Fabrication And Characterization ◽  
Low Magnetic Field ◽  
Magnetic Field Condition

This paper presents fabrication and characterization of micro-patterned magnetorheological elastomeric structures composed of magnetorheological fluid (MRF) sandwiched with magnetorheological elastomeric (MRE) materials. The MRE structures are made of polydimethylsiloxane (PMDS) with and without an additive of carbonyl iron (CI) particles with a size range of 6–9 um and the MRF is composed of silicon fluid mixed with the CI particles of the same size range. Three different SU-8 master molds of plain, longitudinal, and latitudinal patterns are constructed. Also, four MR elastomeric structures of different CI particle arrangements of isotropic MRE, anisotropic top-to-bottom-aligned MRE, anisotropic side-to-side-aligned MRE, and pure PDMS for each SU-8 master mold are fabricated. MRE structures are then characterized by using a tensile testing machine under a normal condition (off-state) and a low magnetic field condition (on-state). The tensile tests were performed to experimentally investigate their tunable properties. Later, the data gathered are compared for different conditions.

An Alternative Protocol for Determining Viscoelastic Material Properties Based on Tensile Tests Without the Use of Poisson’s Ratios

2007 ◽  
Author(s):  
Abraham Shtark ◽  
Hagay Grosbein ◽  
Guy Sameach ◽  
Harry H. Hilton
Keyword(s):  
Constitutive Relations ◽  
Testing Machine ◽  
Tensile Tests ◽  
Experimental Results ◽  
Tensile Creep ◽  
Time Interval ◽  
Tensile Testing Machine ◽  
Experimental Protocols ◽  
Poisson's Ratios ◽  
Poisson’S Ratios

Analytical and experimental protocols are formulated and outlined in detail wherein unidirectional tensile creep or relaxation experiments are performed on viscoelastic specimen. A combination of a photogrametric system and a tensile testing machine provides stress data in the loaded direction and strains in both longitudinal and transverse directions. The data is integrated through the use of the integral constitutive relations, and produce values for the creep compliance parameters. Subsequently, the viscoelastic Young’s, shear and bulk moduli are determined without the use of viscoelastic Poisson’s ratios. Experimental results indicate strong time, stress and stress history dependencies of viscoelastic PRs. Current experimental results are compared with traditional methods based on assumed time independent Poisson ratios. Maximum errors in strain values from 160% to 205% for the constant PR approach are demonstrated when its results are compared to results for the experimental time interval.

DIRECTION-DEPENDENT AND MULTIAXIAL STRESS-SOFTENING BEHAVIOR OF CARBON BLACK–FILLED RUBBER

2014 ◽  
Vol 87 (1) ◽  
pp. 139-151 ◽  
Author(s):  
Hasan Kahraman ◽  
Edmund Haberstroh
Keyword(s):  
Mechanical Behavior ◽  
Anisotropic Material ◽  
Tensile Testing ◽  
Testing Machine ◽  
Material Behavior ◽  
Experimental Results ◽  
Mullins Effect ◽  
Induced Anisotropy ◽  
Tensile Testing Machine ◽  
Biaxial Tensile Testing

ABSTRACT The mechanical behavior of filled rubbers depends on the maximum stretch previously reached and consequently on the induced stress softening. This softening effect is referred to as the Mullins effect. Current investigations point out that the Mullins effect exhibits a significant directional dependence, which calls for an anisotropic material model. But for the formulation and validation of anisotropic material models, there is still a lack of suitable experimental data. For this the purpose, experiments based on chloroprene rubber (CR) are reported. To trace the anisotropic Mullins effect, the standard test method for characterization of the isotropic mechanical behavior must be extended. The appropriate type of specimen enables us to perform multiple load steps with alternating load directions. After repeated stretching in the same direction, a subsequent first uniaxial loading in any other direction is characterized by a stiffer stress–strain behavior compared with the stabilized curve of the previous primary load. Hence, the experimental results confirm the deformation-induced anisotropy. To identify the multiaxial material behavior after the prestretching in one direction, a biaxial tensile-testing machine is developed. A specific property of the biaxial tensile-testing machine is the independent control of both the loading axes. Thus, the rubber material can be subjected to arbitrary loading histories. Therefore, a cross-shaped specimen with four arms is used. Multiple slits parallel to the sides on each arm ensures the homogenous uniaxial load condition in the primary load. In the secondary load step, the loading axis, which was previously inactive, is moved in a uniform manner as the master axis or in any arbitrary defined ratio. The experimental results confirm the deformation-induced anisotropy of the Mullins effect. In summary, the material behavior significantly results from the deformation mode and the loading direction applied in the loading history.

Mechanical Behavior of a Pt-Cr Jewelry Alloy Hardened by Nano-Sized Ordered Particles

2004 ◽  
Vol 842 ◽  
Author(s):  
Kamili M. Jackson ◽  
Miyelani P. Nzula ◽  
Silethelwe Nxumalo ◽  
Candace I. Lang
Keyword(s):  
Binary Systems ◽  
Cold Working ◽  
Testing Machine ◽  
Tensile Tests ◽  
Heat Treatments ◽  
Small Scale ◽  
Tensile Testing Machine ◽  
Materials Engineering ◽  
Hardness Tests ◽  
The Cost

ABSTRACTThe materials engineering of platinum jewelry is interesting because only 5wt% can be used for alloying in order to maintain hallmarking. However, pure platinum is very soft and must be alloyed in order to be used effectively as jewelry. In several binary systems an increase in hardness has been found after cold working and annealing at low temperatures. The hardening in these alloys has shown to be a result of nano-sized ordered particles. In particular, the existence of the ordered particles has previously been confirmed for a Pt-Cr alloy by TEM. Extensive work has been done on the Pt-Cr alloy to understand the crystal structure and mechanisms of the ordered phase. Hardness tests were performed to measure mechanical properties after various heat treatments. In addition, tensile tests were conducted using a small-scale tensile testing machine. An 8mm long specimen is used, which significantly reduces the cost of the specimens while providing necessary properties. Tensile tests on the Pt-Cr alloys at various post deformation heat treatments show an increase in tensile strength with no effect on ductility. They confirm results of the hardness tests while providing additional properties data. In addition, the results show a fairly good relationship between strength and hardness.

scholarly journals Effect of Nanometric Metallic Hydroxides on the Flame Retardant Properties of HDPE Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
F. I. Beltrán-Ramírez ◽  
L. F. Ramos-deValle ◽  
E. Ramírez-Vargas ◽  
S. Sánchez-Valdes ◽  
A. B. Espinoza-Martínez ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Tensile Properties ◽  
Cone Calorimeter ◽  
Flame Retardants ◽  
Testing Machine ◽  
Tensile Tests ◽  
Tensile Testing Machine ◽  
Cone Calorimeter Test ◽  
Ul 94 ◽  
Flame Retardant Properties

The effect of nanometric magnesium and aluminum hydroxides on the flame retardancy of high density polyethylene was studied. Additionally, the effect of maleic anhydride grafted polyethylene (PEgMA) and methyl acrylate grafted polyethylene (EMA) compatibilizers, on the tensile properties, was also studied. Morphological characterization of nanocomposites was carried out by means of scanning transmission electron microscopy (STEM). Flame retardant properties of nanocomposites were evaluated by the UL-94 horizontal and vertical tests as well as by cone calorimeter tests. Thermal degradation behavior was analyzed with a thermogravimetric analyzer (TGA). Tensile tests were carried out according to ASTM D 638-03 in an Instron 4301 tensile testing machine. From STEM images, a good dispersion of flame retardants (MH and ATH) in the polymer matrix was observed, which was reflected in the flame retardant properties. Results showed that the combination of nanometric MH and ATH produced excellent flame retardant properties, achieving a classification of V0 in the UL-94-V test and producing the lowest peak of heat release rate (PHRR) and the lowest total heat released (THR) in the cone calorimeter test. Finally, the addition of compatibilizer, especially PEgMA, resulted in much better tensile properties as compared to the noncompatibilized composition, maintaining the flame retardant properties.

scholarly journals Stress-Strain Behavior – Deformation Degree Relationship Investigation of Alloy CrNi60WTi

2021 ◽  
Vol 65 (1) ◽  
pp. 105-107
Author(s):  
Yaroslav Kosmatskiy ◽  
Nikolai Fokin ◽  
Kseniya Yakovleva ◽  
Vladislav Nikolenko ◽  
Boris Barichko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cold Deformation ◽  
Testing Machine ◽  
Tensile Tests ◽  
Outer Diameter ◽  
Test Results ◽  
Deformation Degree ◽  
Tensile Testing Machine ◽  
Strain Behavior ◽  
Static Tensile

The article presents the results of a research of the dependence of the mechanical properties of the CrNi60WTi alloy on the degree of cold deformation. As part of the study, five samples were taken from a pipe with an outer diameter of 89.0 mm and a wall thickness of 11.0 mm. The samples were cold-deformed to varying degrees and static tensile tests were performed on an SSI MTSInsight tensile testing machine. Based on the test results, the dependences of the mechanical properties on the degree of cold deformation were calculated.

Effect of Vanadium on the Microstructure and Property of Rebar Steel

2018 ◽  
Vol 928 ◽  
pp. 269-272
Author(s):  
Zi Shan Yao ◽  
Guang Xu ◽  
Ming Xing Zhou
Keyword(s):  
Mechanical Property ◽  
Tensile Testing ◽  
Induction Furnace ◽  
Testing Machine ◽  
Tensile Tests ◽  
Bearing Steel ◽  
Vacuum Induction Furnace ◽  
Tensile Testing Machine ◽  
Base Steel ◽  
Microalloying Elements

Rebar steel is used in the construction of various buildings. Vanadium (V), one of microalloying elements, is often added in the rebar steel to improve mechanical property. In order to analyse the effect of V on the microstructure and property of rebar steel, 0.043 wt.% V was added in a 20MnSi rebar steel. The base steel and V added steel were refined in a 50 kg vacuum induction furnace and rolled to plates of 14 mm thick. The mechanical properties of two steels were compared by tensile tests on a Wan-10000 tensile testing machine. The microstructure and precipitation of two steels were analysed by SEM and TEM observations. The microstructures of two steels consist of ferrite and pearlite. However, the grains of V bearing steel are finer. Moreover, fine nanoscale precipitates of V can be observed in V bearing steel. Therefore, the mechanical property of V addition rebar steel is improved by gain refinement strengthening and precipitation strengthening.

Modeling hyperviscoelastic behavior of elastomeric materials (HDPE/POE blend) at different dynamic biaxial and uniaxial tensile strain rates by a new dynamic tensile-loading mechanism

2019 ◽  
Vol 52 (4) ◽  
pp. 285-303
Author(s):  
E Aligholizadeh ◽  
M Yazdani ◽  
H Sabouri
Keyword(s):  
Tensile Strain ◽  
Testing Machine ◽  
Tensile Loading ◽  
Tensile Tests ◽  
Impact Testing ◽  
Material Behavior ◽  
Uniaxial Tensile ◽  
Strain Rates ◽  
Elastomeric Materials ◽  
Dynamic Tensile Loading

This article presents a new model developed to investigate hyperviscoelastic behavior of elastomeric materials/polyolefin elastomers (HDPE/POE blend) under dynamic biaxial and uniaxial tensile loading. Various strain energy functions (SEF) have been used in this model, and their capability to predict hyperelastic behavior of the aforementioned materials was validated by experimental data. In the experimental part, a new dynamic tensile-loading mechanism was designed and developed to be mounted on a drop-weight impact-testing machine. As a novelty, this mechanism has the ability to perform either uniaxial or biaxial dynamic tensile tests for any type of material, especially for investigating the hyperviscoelastic behavior of materials like elastomers at various strain rates. In addition, a new hyperviscoelastic model has been developed for elastomeric material, which can predict the behavior of the material well at different strain rates. By increasing the strain rate in the dynamic biaxial and uniaxial loading, Pucci–Saccomandi and Yeoh SEF predicted the dynamic behavior of material well due to its lower root mean square error. In fact, in this case, these functions are more capable than Mooney–Rivlin, Neo-Hookean, and polynomial SEF in predicting the effect of the strain rates. In addition, the results show that Yeoh SEF performs much better than the other SEFs in predicting the material behavior in cases of dynamic biaxial and uniaxial tensile strain. The results also indicated that the newly designed mechanism was capable of performing dynamic tensile loading and extracting its accurate results and could reduce the cost of testing compared to other methods.

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