physics

Plane strain compression test

Plane strain compression test is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Plane strain compression test rather than just read about it. In short: The plane strain compression test is a specialized test used on some materials, ranging from metals to soils. Metals One variation of the test is also known as the Watts-Ford test.

Key takeaways

Plane strain compression test belongs to physics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Plane strain compression test to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Plane strain compression test from memory before moving on to harder problems.

Reference excerpt

The plane strain compression test is a specialized test used on some materials, ranging from metals to soils.

Metals One variation of the test is also known as the Watts-Ford test. It is an engineering test, and is a particularly specialized way of determining some of the material characteristics of the metal being tested, and its specialization can be summarized by this quote:

The test is useful when the sheet pieces are too small for a tensile test of a balanced biaxial test. It can give stress-strain curves up to considerably higher strains than tensile tests.

Plane-strain compression testing is typically used for measuring mechanical properties and for exploring microstructure development in the course of thermomechanical treatment. During the test the specimen is placed between the punches and the constrain plates. When the upper punch is pushed down during the material test, the specimen is extended to horizontal directions. Friction between the tool and the specimen can be reduced by applying lubricants, such as graphite, MoS2, glass or PTFE(Teflon). The testing essentially consists of a thin metal bar being compressed by two equally wide compressive strips, which are located of opposite sides of the thin bar. Then, over a range of increasing loads on the bar, the compressive forces lead to the thickness of the metal bar being reduced. This change of thickness is then measured sequentially after each loading, and after some mathematics a stress-strain curve can be plotted. The advantages of the Watts-Ford test are that it is convenient for testing thin sheets or strips, it is similar to a rolling process (in manufacturing analyses), frictional effects may be minimized, there is no 'barrelling' as would occur in a cylindrical compression test, and the plane strain deformation eases the analysis. Stress-strain curve The stress-strain curve is the relationship between the stress (force per unit area) and strain (resulting compression/stretching, known as deformation) that a particular material displays; stress–strain curves of various materials differ widely, and different tensile tests conducted on the same material yield different results depending upon the temperature of the specimen and the speed of the loading. When performing Watts-Ford tests, temperatures of the metal specimens will vary from 800 to 1100 °C and strain rates of (0.01- 10 s-1).

Pressure The average pressure on a unit of area of the contact surface between the punch and the specimen is expressed as: P= F/(wb), where F is force, w is the punch width, b is the specimen width.

See also Compression (physics) Compressive strength Shear stress

Citations

Illustrations

Worked examples

Example 1 — a first encounter with Plane strain compression test

Start with the simplest possible case. Write down what Plane strain compression test claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Plane strain compression test before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Plane strain compression test ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Plane strain compression test

In research: Plane strain compression test appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Plane strain compression test in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Plane strain compression test is common in secondary-school and first-year university syllabi. It links to neighbouring topics Continuum mechanics, Materials testing, so understanding it makes those chapters shorter.
In everyday life: Look for Plane strain compression test outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Plane strain compression test in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Plane strain compression test means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Plane strain compression test out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Plane strain compression test in simple terms?

The plane strain compression test is a specialized test used on some materials, ranging from metals to soils. Metals One variation of the test is also known as the Watts-Ford test.

Why does Plane strain compression test matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Plane strain compression test?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Plane strain compression test.