answersLogoWhite

0


Best Answer

The specimen's shape is usually defined by the standard or specification being utilized, e.g., ASTM E8 or D638. Its shape is important because you want to avoid having a break or fracture within the area being gripped. So, standards have been developed to specify the shape of the specimen to ensure the break will occur in the "gage length" (2 inches are frequently used) by reducing the cross sectional area or diameter of the specimen throughout the gage length. This has the effect of increasing the stress in the gage length since stress is inversely proportional to the cross sectional area under load, .

User Avatar

Wiki User

14y ago
This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: Why is the tensile test sample dumbbell shape?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Related questions

What is tensile test?

A sample is tested using a tensile test machine by loading it in a direction along its axis. The load is measured with a load cell, and when the sample breaks its tensile strength is determined by dividing the failure load by its area.


How tensile test is made on a material?

A sample coupon of the material is made up, usually in the shape of a dog bone per standards of ASTM. The sample is placed into a tensile testing machine such as made by Instron. The sample is grasped at the ends of the dog bone. This machine has a load cell in it, and the machine is commanded to move relative to its fixed base and stretch the sample, resulting in stress and strain of the material. When the material breaks, the tensile strength is noted. The break stress is the strength divided by the area of the sample of the dog bone center section. If you want yield point, this can be obtained also from plots integral with the software of the test set up. If you want to measure tensile modulus, you would need a strain gage device or extensometer . This is not needed for tensile strength only.


What methods are used for tensile test of mild steel?

tensile test


How Do you calculate the Ultimate Tensile Strength of a Material?

You take coupon sample, usually and approved shape and size, and pull it to failure with a tensile test machine such as those made by Instron. It has a load cell that measures the load it takes to break the sample. Then you simply divide by the sample cross section area to get the tensile strength


Why Tensile Properties of most brittle materials are accessed by transverse bending test and not ascertain by tensile test?

why the tensile properties of most brittle materials are accessed by transverse bending tests and not ascertain by tensile tests


How is tensile strength testing preformed?

Tensile strength testing is performed by pulling on a substance until it breaks. A tensile test is known for being the most fundamental type of mechanical test that can be performed on a material.


What is importance of tensile strength test?

yes


What is ASTM standard for tensile test?

E8


In splitting tensile test actually you are getting compressive strength but in answer you are writing it as tensile strength why?

The splitting tensile test specimen is subjected to a compressive load. For brittle matrixes such as cementitious products, the compressive strength is typically around an order of magnitude higher than tensile strength. On a microstructure scale, the compressive forces are trying to crush the individual crystallites while the tensile forces only have to fracture the connections between crystallites. The splitting tensile test specimen fails due to the tensile forces generated as it distorts perpendicular to the applied compressive load. In practice, a loading cap on the loading faces of the specimen generates a compressive column in the sample and the true failure is in shear along this compressive column due to the tensile forces. In practicality, this test is also useful for flexural testing of weak composite materials where in both cases a compressive load generates tensile forces that initiate a failure that travels to the neutral axis resulting in shear as well.


What is a straight pull tensile test?

A tensile test machine is designed to give a straight line pull on a member so that it measures only direct tensile stress given as the force applied divided by the member area


What is the difference between toughness from impact test and toughness from tensile test?

A tensile test is performed by stretching the material until it breaks. An impact test is performed by applying a sudden shock to the material so that it fractures.


When a tensile strength test specimen begins to deform permanently it has reached its?

Tensile yield point or yield strength