Description

Stress rupture testing is similar to creep testing except that the stresses used are higher than in a creep test.  Stress rupture testing is always done until failure of the material. 

In creep testing the main goal is to determine the minimum creep rate in stage II.  Once a designer knows the materials will creep and has accounted for this deformation a primary goal is to avoid failure of the component.

Stress rupture tests are used to determine the time to cause failure.  Data is plotted log-log as in the chart above.  A straight line is usually obtained at each temperature.  This information can then be used to extrapolate time to failure for longer times.  Changes in slope of the stress rupture line are due to structural changes in the material.  It is significant to be aware of these changes in material behavior, because they could result in large errors when extrapolating the data.

We perform composite creep mechanical preprint resistance strength and brittle creep damage ductile engineering failure fatigue mechanics.

ASTM E139 - Standard Test Method for Conducting Creep, Creep-Rupture, and Stress-Rupture Tests of Metallic Materials

The method, ASTM E139, determines the amount of deformation as a function of time (creep test) and the measurement of the time for fracture to occur when sufficient load is present (rupture test) for materials when under constant tension loads at constant temperature. It also describes the essential requirements for testing equipment.

Rupture tests, properly interpreted, provide a measure of the ultimate load-carrying ability of a material as a function of time. Creep tests measure the load-carrying ability for limited deformations. The two tests supplement each other in defining the load-carrying ability of a material.