What term is used to describe a permanent and cumulative deformation of the turbine blades of a turbojet engine?

Creep

Explanation:

Creep is a type of deformation that occurs when continuous and long term mechanical stresses are being subjected to a material. Material deformation is observed even if the stresses are below the yield strength of the material, . The effect of creep is more pronounced if there is an application of heat.

In a study of turbine blades it has been shown that at the location where creep is present there was micro-structural degradation. In other places there was no micro-structural degradation.

a high pressure system is a dense air mass that is usually cooler and drier than the surrounding air. a low pressure system is a less dense air mass that is usually wetter and warmer than the surrounding air.

in general, areas that experience high atmospheric pressure also experience fair weather. low pressure systems can cause the formation of clouds and storms. air usually flows from areas of high pressure to areas of low pressure..