Compressive Strength

This number describes how much of a non-moving load a bar can take before it is crushed. Units are normally
thousands of pounds per square inch. (103 psi) - Mega Pascals (mPa). Higher numbers indicate stronger materials
which can withstand a heavier load before they break.

Compressive Behaviour of Composites

Rapra Review Report No. 94, 1997

C. Soutis, Imperial College of Science, Technology & Medicine

Fibre-reinforced polymer-based composites have widespread uses throughout industry, often in the most hostile and
demanding environments. The behaviour of these composites under tensile loading has been investigated in depth,
and well reviewed, but their compressive properties have received less attention. However the compressive strength
of current composite systems is typically 60-70% of their tensile strength, due to the fibre microbuckling failure
mode, and it has become design critical in many instances, especially in notched, impacted and extreme
environmental conditions. It is the compressive behaviour of composites, and particularly their failure mechanisms
under static and fatigue loading, which are evaluated in this Rapra Review Report.

In this report Dr. Costas Soutis of Imperial College reviews the most important studies undertaken of the compressive
failure mechanisms encountered in modern composite materials. He first considers the behaviour of unidirectional
laminates, followed by unnotched and notched multidirectional structures. He considers existing theoretical models
which predict the compressive strength of unidirectional and multidirectional lay-ups, and fracture models of
compressive failure from a circular open hole. Mechanical behaviour under compressive fatigue loading is also covered.

The review is extensively referenced, and supported by an indexed section containing more than 500 abstracts of key
papers selected from the Rapra Abstracts database, which will provide the reader with much additional detail and
experimental data.

http://www.rapra.net/pubs/m15.htm

Compressive strength may be defined as the measured maximum resistance to axial loading