Impact Machine for Rubber Testing. Determining the Stress-Strain Diagram at High Speed

1937 ◽  
Vol 10 (2) ◽  
pp. 317-328 ◽  
Author(s):  
Geo J. Albertoni
Keyword(s):  
Tensile Properties ◽  
High Speed ◽  
Standard Procedure ◽  
Tensile Tests ◽  
Strain Diagram ◽  
Stress Strain ◽  
Impact Machine ◽  
Actual Performance ◽  
Stress Strain Relation

Abstract IN CONTRAST to the ordinary standard procedure at low speed, various methods have been devised to carry out tensile tests of rubber under rapid application of load, with the purpose of securing more definite indications, at a speed in agreement with actual performance. The application of those methods to the study of the tensile properties of rubber stocks goes as far back as 1910, when Beadle and Stevens (1) made use of the pendulum to investigate these properties. Their work applied to rubber compounds of different compositions and different loadings. More recently, Van Rossem and Beverdam (2) presented a set of results tending to prove an optimum in the tensile properties, coinciding with the best cure as determined by practical observation. However, all experiments, previous to those here reported, are limited to the determination of the tensile strength of rubber, and no attempt was made to extend the investigations to the determination of the resistance of rubber at different elongations. The machine here illustrated is designed to measure not only the energy absorbed at break, under conditions of high speed, by impact, but also the stress-strain relation.

The Influence of the Test-Specimen on the Results Obtained In Tensile Tests of Soft Vulcanized Rubber Mixtures

1953 ◽  
Vol 26 (2) ◽  
pp. 465-480
Author(s):  
R. Herzog ◽  
R. H. Burton
Keyword(s):  
Natural Rubber ◽  
Tensile Properties ◽  
Test Specimen ◽  
Tensile Tests ◽  
Stress Strain ◽  
Vulcanized Rubber ◽  
Different Types ◽  
Small Test ◽  
Soft Rubber

Abstract The small test-specimen of the VSM-1 type should not be used for measuring the tensile properties of pure-gum vulcanizates; instead, the VSM-1a type of test-specimen should be used for such vulcanizates. Results obtained with the different types of test-specimen differ greatly; hence, in reporting the results of any tests of this kind, the type of test-specimen used should be stated, and only results obtained with one particular type of test-specimen should be compared. For example, substitution of the VSM-2 type of test-specimen by the KTA-II type of test-specimen, which is of approxmately the same size, unfortunately does not result in any better agreement. Based on these differences, which in the case of natural rubber have been found to vary from one type of vulcanizate to another, it is natural to expect corresponding unpredictable differences with various synthetic elastomers. The determination of stress-strain properties of soft rubber vulcanizates is, therefore, fundamentally a problem of agreement on methods of testing, i.e., of standardization.

Investigating the in-plane mechanical behavior of single-ply quasi-unidirectional glass fiber/polypropylene composites

2017 ◽  
Vol 37 (4) ◽  
pp. 401-409 ◽  
Author(s):  
Zhanyu Zhai ◽  
Christian Gröschel ◽  
Dietmar Drummer
Keyword(s):  
Tensile Stress ◽  
Glass Fiber ◽  
Tensile Tests ◽  
Stress Strain ◽  
Polypropylene Composites ◽  
Strain Relation ◽  
Stress Strain Relation ◽  
Pp Composites ◽  
Experimental Values ◽  
First Time

Abstract The objective of this study was to determine the engineering constants and off-axis tensile stress-strain relation of single-ply quasi-unidirectional (UD) glass fiber (GF)/polypropylene (PP) composites using the new approach. A series of off-axis tensile tests of quasi-UD composites were carried out. In this study, Puck’s interfiber fracture criterion was expanded for the first time to estimate the off-axis tensile stresses of UD composites. With the experimental values, the shear properties were obtained through the curve-fitting methods. Damage mechanisms were demonstrated to evolve with the loading angle. By comparison to experimental data, the Hahn-Tsai equation, together with the transformation equation, was found to be adequate to describe the off-axis tensile stress-strain relation of single-ply quasi-UD GF/PP composites.

An Improved Method of Determining the Disturbed State Concept Model Parameters

2014 ◽  
Vol 919-921 ◽  
pp. 1345-1349
Author(s):  
Wei Lu ◽  
Jia Jun Pan
Keyword(s):  
Triaxial Compression ◽  
Model Parameters ◽  
Improved Method ◽  
Stress Strain ◽  
Material Parameters ◽  
Concept Model ◽  
Strain Relation ◽  
Stress Strain Relation ◽  
Disturbed State Concept

The method of postulate of relatively intact model in the disturbed concept model is reached. Because it is more difficult to assume relatively intact curve by observed experimental data, a method which could automatically calculate the stress strain relation curve of relative intact by triaxial compression test data is raised, so that the determination of material parameters becomes easier, and the improved method is verified by numerical calculation. The results show that this method can effectively determine the stress strain relation curve of relative intact.

In Vivo Determination of the Stress-Strain Relation of the Human Myometrium

1976 ◽  
Vol 55 (4) ◽  
pp. 325-331 ◽  
Author(s):  
Ingemar Joelsson ◽  
Lennart Gidlund ◽  
Bo Anzén ◽  
Axel Ingelman-Sundberg
Keyword(s):  
Human Myometrium ◽  
Stress Strain ◽  
Strain Relation ◽  
Stress Strain Relation

Comparison of Manufacturing Techniques Subject to High Speed Impact

2014 ◽  
Author(s):  
Kenneth Gollins ◽  
Jack Chiu ◽  
Feridun Delale ◽  
Benjamin Liaw ◽  
Ali Gursel
Keyword(s):  
High Speed ◽  
Mechanical Performance ◽  
Tensile Tests ◽  
Compression Molding ◽  
Epoxy Composites ◽  
Fiber Density ◽  
Vacuum Infusion ◽  
High Speed Impact ◽  
Manufacturing Techniques

In this paper we compare two manufacturing techniques namely vacuum infusion and compression molding, used in manufacturing S2 glass fabric/epoxy composites for high-speed impact applications. Even though compression molding and vacuum infusion are two widely used manufacturing techniques, the resulting product may be very different. Compression molding has the advantage of achieving a much higher fiber density for the same thickness. With a higher fiber density, the composites made by compression molding have better mechanical properties than a composite made by vacuum infusion. However, vacuum infusion is faster and more economical. The mechanical performance of the composites manufactured by these two processes are compared by performing tensile tests and high speed impact tests for the determination of the limit speed V50. For the same number of plies, preliminary results for compression molded specimens indicate a 50% increase in stiffness and a 40% increase in strength. Also, for panels of the same thickness, the V50 was higher for compression molding specimens.

Determination of Full Range Stress-Strain Behavior of Pipeline Steels Using Tensile Characteristics

2010 ◽  
Author(s):  
Stijn Hertele´ ◽  
Wim De Waele ◽  
Rudi Denys
Keyword(s):  
Full Range ◽  
Tensile Tests ◽  
Proof Stress ◽  
Stress Strain ◽  
Pipeline Steels ◽  
Strain Behavior ◽  
Parameter Values ◽  
Near Future ◽  
Strain Model

It is standard practice to approximate the post-yield behavior of pipeline steels by means of the Ramberg-Osgood equation. However, the Ramberg-Osgood equation is often unable to accurately describe the stress-strain behavior of contemporary pipeline steels with a high Y/T ratio. This is due to the occurrence of two distinct, independent stages of strain hardening. To address this problem, the authors recently developed a new ‘UGent’ stress-strain model which provides a better description of those steels. This paper elaborates a methodology to estimate suited parameter values for the UGent model, starting from a set of tensile characteristics. Using the proposed methodology, good approximations have been obtained for a preliminary series of eight investigated stress-strain curves. Next to all common tensile characteristics, the 1% proof stress is needed. The authors therefore encourage the future acquisition of this stress level during tensile tests. Currently, the authors perform a further in-depth validation which will be reported in the near future.

The Oxidation Products of Rubber

1939 ◽  
Vol 12 (2) ◽  
pp. 225-234
Author(s):  
A. van Rossem ◽  
P. Dekker
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Tensile Properties ◽  
High Speed ◽  
Accelerated Aging ◽  
Direct Determination ◽  
Oxidation Products ◽  
Vulcanized Rubber

Abstract In their summary of the aging of vulcanized rubber, Porritt and Scott state that three factors are responsible for the changes in mechanical properties of vulcanized rubber during aging, viz.: (a) oxidation of the rubber; (b) after-vulcanization; (c) some colloidal change of the rubber, sometimes termed aggregation. Of these factors, oxidation is by far the most important because it is responsible for the decrease in mechanical properties, which leads to the general deterioration of rubber from a technical standpoint. It was Marzetti who proved that the decrease of mechanical properties in accelerated aging is due to oxidation. Later, Kohman confirmed this in a more concise way and showed that even such small amounts as 0.5% of oxygen absorbed by vulcanized rubber are sufficient to decrease tensile properties to 50% of their original value. When studying aging, three ways of tackling this problem are possible, viz.: (1) Investigations of the mechanical properties, either under normal conditions, or under special conditions such as elevated temperature or high speed. (2) Determination of oxidation products, which are formed during oxidation of the rubber. (3) Direct determination of the amount of oxygen which is absorbed by the rubber. It is clear that any of these methods may be combined with accelerated aging tests.

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