What Does Tensile Strength Mean?
Tensile strength is the maximum amount of tensile stress a material can withstand before it fails or breaks. It is a measure of the material's ability to resist deformation under tension or stretching forces.
When high tensile loads are applied, ductile and brittle materials will approach failure. This process begins with a uniform deformation throughout the sample followed by an increase in length and a decrease in width at the same rate.
Corrosionpedia Explains Tensile Strength
Tensile strength is an important property of materials used in engineering and manufacturing applications. It is a critical factor in designing structures, such as buildings, bridges and aircraft, that can withstand forces due to tension or stretching. It is also important in the design of products that are subject to pulling or stretching forces, such as ropes, cables and wires.
Tensile strength is usually determined by conducting a tensile test, which involves applying an axial load to a test specimen until it fractures. The load is applied using a tensile testing machine, which measures the amount of force required to break the specimen. The maximum load the specimen can withstand before it fractures is the tensile strength.
Tensile strength is usually reported in units of force per unit area, such as pounds per square inch (psi) or megapascals (MPa). The tensile strength of a material depends on its composition, structure and processing history. For example, steel with a higher carbon content tends to have a higher tensile strength than steel with a lower carbon content.
A material's tensile strength is an important factor in determining its suitability for a particular application. For example, in the aerospace industry, the tensile strength of materials used in aircraft structures is critical to ensure the safety and reliability of the aircraft. Similarly, in the construction industry, the tensile strength of materials used in building structures, such as steel and concrete, is critical to ensure the structures can withstand the forces of wind, earthquakes and other environmental factors.
Tensile strength can also be affected by various factors, such as temperature, strain rate and fatigue. For example, the tensile strength of some materials may decrease at high temperatures, while others may exhibit an increase in strength. Similarly, the tensile strength of a material may decrease as the rate of deformation increases. Fatigue can also affect the tensile strength of a material, causing it to decrease over time under repeated loading.
Ultimate tensile strength an intensive property, meaning it depends on the sample size, which measures the amount of stress a material can withstand before it moves from experiencing uniform plastic deformation to experiencing local concentrated deformation. Necking starts at this point.
Because necking can cause failure and may be life-threatening, it is important to consider this parameter while selecting suitable materials for an application. (For more on corrosion control using design methods, read: How to Control Corrosion by Improving Design.)
Designing for ultimate tensile strength means part of the asset will permanently deform once it's subjected to the load for which it was designed. This deformation may cause the material’s crystal structure to change, making it no longer able to function.
In case of cold-drawn steel bars, the tensile strength is increased by cold drawing where the bar is drawn through a die reducing its outer diameter. It is critical for shafts used in various applications.