Design and Technology – Quality systems | e-Consult

Here are three material testing methods suitable for assessing balsa wood for a model aeroplane:

• Tensile Testing: This method involves pulling a specimen of balsa wood until it fractures. The principle is to measure the force required to elongate the material to a specific point.

  Information provided: Tensile testing determines the tensile strength of the wood – the maximum stress it can withstand before breaking. This is crucial for ensuring the wings and other load-bearing parts can withstand aerodynamic forces. It also provides information on the Young's modulus, which indicates the stiffness of the wood.

• Flexural Testing (Bend Test): A specimen is supported at both ends and a load is applied to the middle, causing it to bend. The principle is to measure the force required to deflect the wood a specific distance.

  Information provided: Flexural testing assesses the wood's ability to resist bending. This is important for components like fuselage sections that experience bending loads. It provides information on the flexural strength and modulus of rupture.

• Shear Testing: This method involves applying a force parallel to the surface of the balsa wood, causing it to shear or break. The principle is to measure the force required to cause a specific amount of shear deformation.

  Information provided: Shear testing determines the wood's resistance to forces that act parallel to its surface. This is relevant for joints and areas where forces are applied tangentially. It provides information on the shear strength of the wood.