Final answer:
To calculate the thermal stress for high temperature and pressure service, use the formula where stress equals the coefficient of thermal expansion multiplied by Young's modulus and the temperature change. The material's tensile strength sets the maximum allowable stress, which must exceed the expected thermal stress.
Step-by-step explanation:
Thermal Stress in High Temperature and Pressure Service
When designing an experiment for services involving high temperature and high pressure, understanding the maximum allowable stress for a material is crucial. This measure is dependent on the material's properties, such as Young's modulus, and the temperature change it undergoes. The concept of thermal stress is significant in this context. Thermal stress is generated when there is a change in temperature of a material that is restricted from expanding or contracting.
To calculate the thermal stress due to a temperature change, we typically use the formula:
σ = α E ΔT
where σ is the stress, α is the coefficient of thermal expansion, E (Young's modulus) represents the rigidity of the material, and ΔT is the temperature change.
The maximum allowable stress is often dictated by the material's tensile strength and can be affected by factors such as temperature. It's the stress value beyond which the material will experience permanent deformation or breakage. For engineering applications, it's vital to select materials with a maximum allowable stress that exceeds the expected thermal stress under the given service conditions.