Start With the Question

Before applying a load, we need to know what the test is intended to tell us.

Are we testing a connection, a wall component, a beam, a complete assembly or something else? Are we interested in stiffness, movement, ultimate strength, repeated loading or a particular failure mode?

A test without a clearly defined question can produce very accurate measurements of something that was not particularly useful.

Show the Rig

The test setup is part of the result.

Photographs and diagrams should show the specimen, supports and restraints, where the load was applied and where displacement or other measurements were taken.

Dimensions, timber condition, connection geometry and other relevant variables belong with the test rather than being left to assumption.

Force Without Displacement Is Half the Story

Knowing that a component carried a particular force is useful. Knowing what it did while carrying that force is usually more useful.

Where appropriate, we record applied force together with displacement. That allows the behaviour of the component to be seen as the load increases rather than reducing the entire test to one maximum number.

A load-displacement graph can show stiffness, changes in behaviour, permanent deformation and the point at which something begins to fail.

Failure Is Data

If a test is taken to failure, the failure mode matters.

Did the wood crush? Did it split? Did a connection move? Did a fastener fail? Did the specimen remain intact while something else in the test setup reached its limit?

And if the test was stopped without failure, that matters too. "Held X load" and "failed at X load" are not the same statement.

No Hero Numbers

A photograph of a large load and one impressive peak value can make a good advertisement. It does not tell an engineer very much.

When we publish a result, we want enough information beside it to understand what the test actually demonstrated.

• What was tested?
• What were the relevant dimensions and material conditions?
• How was it supported and restrained?
• Where and how was the load applied?
• What was measured?
• How did the specimen behave as the load increased?
• Was permanent deformation observed?
• Did it fail?
• If it failed, how did it fail?

Then the number means something.