flexural test

mechanical testing – flexural test for plastic and composite material

The essence of a flexural test is to determine the flexibility of a material by measuring the force required to bend a beam under a specified loading condition. Typically, a three-point bending condition is used following ASTM D790. 

The sample preparation process for a three-point bend test is relatively simple, as a typical sample is a simple rectangular beam with specified dimensions according to ASTM D790 and ISO 178. The length of the specimen must exceed the distance between the supports and a force is applied to the midpoint of the specimen. Nevertheless, one-point bend test and four-point bend test are also available. 

The three-point bend flexural test employs a simply-supported setup, where the rectangular bar is placed on two supports and deformed by a single central load as illustrated below.

flexural test

There are a variety of standards related to three-point bend test, including ISO 178, ISO 14125, ASTM D672, ASTM D55365, IPC TM-650, and IEC 61189-2:TM20. This test is suitable for plastics and composite materials. Impact uses an Instron universal tester (3382) to carry out flexural testing. In addition, we are also equipped with a special environmental chamber from Instron, which allow us to carry out at sub-ambient or above ambient conditions.

In summary, flexural testing can aid designers & moulders to select the most suitable material for the intended purpose by understanding the following properties:

-Flexural Strength
-Maximum Flexural Stress
-Maximum Strain
-Stress at Strain
-Flexural Secant Modulus of Elasticity
-Flexural Chord Modulus of Elasticity
-Failure Mode and Location

Why impact?

impact are a one stop shop. Our team have over 120 years of combined experience in the testing industry and can advise you on what type of accelerated weathering testing you need. No matter the question, product, or standard, contact us today for guidance on testing for your product. With our UKAS accreditation, we can test to anything that falls within the boundaries of our extensive flexible scope. impact will always do their best to help you with your testing needs and our experienced weathering consultant, Jo, will advise you on the best method of testing.

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