- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 31 Oct 2018
In structural engineering, the term 'stiffness' refers to the rigidity of a structural element. In general terms, this means the extent to which the element is able to resist deformation or deflection under the action of an applied force. In contrast, flexibility or pliability is a measure of how flexible a component is, i.e. the less stiff it is, the more flexible it is.
Young’s modulus (E - elastic modulus) is a measure of the stiffness of a material. This is a material constant, independent of the amount of material.
Increasing the stiffness or rigidity of a structural element reduces its deflection under load. This can be done by strengthening its section or increasing its size, but this will generally also increase its cost.
In a structure that is made up of many different structural elements, those elements will carry load proportionate to their relative stiffness. Therefore, the load an element will attract increases the stiffer it is.
 Related articles on Designing Buildings Wiki
Featured articles and news
UK energy policy uncertainty as Welsh project put on hold
What collaborative working achieves and how it can be put in place.
BSRIA publishes the 2019 edition of its small but concise annual databook.
Using QSAND to measure the performance of disaster response.
What U-values are, why they matter and how they are calculated.
The need to ensure that we plan for all aspects of our bio-economy
BSRIA calls on government to reach deeper into the causes of pollution.
George Demetri brings a whole new level of technical knowledge to Designing Buildings Wiki.
Quality professionals need to take an active role in driving the completion process forwards.
The innovations needed to move from rhetoric to realisation.
Creating a sense of place, with radically-low running costs and the highest comfort levels.
A conversation between David Mitchell and Caitlin DeSilvey.