What Does Specific Strength Mean?
Specific strength is a measure of strength equivalent to the yield strength divided by the material density.
It is used most commonly for comparing materials. Engineers are always looking for a material with a high specific strength instead of low mass density. Materials that possess great specific strength were first applied to national aerospace development, medical care and sports projects.
Specific strength is also known as the strength-to-weight ratio or strength/weight ratio.
Corrosionpedia Explains Specific Strength
In material selection, specific strength is an important concept – the materials with the highest specific strengths are typically fibers such as carbon fiber, glass fiber and various polymers, and these are frequently used to make composite materials (e.g. carbon fiber-epoxy). These materials and others such as high-strength steel alloys are widely used in aerospace and other applications where weight savings are more important than material cost.
Materials with high specific strength are developed to meet the requirements of advancing technology. However, their usefulness depends to a large extent on how well they resist corrosion fatigue. Since environment plays a significant role in corrosion, selecting suitable materials in considering specific strength is crucial.
Materials with a high strength and low mass density provide a high specific strength and are ideal for engineers. Carbon fiber reinforced composites (CFRC) possess the highest specific strength. The specific strength of carbon composites are at least two times more than maraging steel, which is characterized with the highest strength among all types of steels. This means that for a certain required strength, the weight of a component is reduced to half if CFRC is used instead of maraging steel.
For automobile applications, this means a lighter vehicle that consumes less fuel. Low crack growth due to impact or fatigue, the ability to produce in directional mechanical properties, and being cost effective in mass production are the other beneficial properties of high specific strength materials like CFRC.