relaxation test การใช้

• The responses for strain hardening, creep, and relaxation tests of such material are shown in Figure 6.
• The responses for strain hardening, creep, and relaxation tests of such a material are shown in Figure 9.
• The residual value that is reached when the stress has plateaued at the end of a relaxation test corresponds to the upper limit of elasticity.
• For some materials such as rock salt such an upper limit of elasticity occurs at a very small value of stress and relaxation tests can be continued for more than a year without any observable plateau in the stress.
• It is important to note that relaxation tests are extremely difficult to perform because maintaining the condition \ cfrac { \ mathrm { d } \ boldsymbol { \ varepsilon } } { \ mathrm { d } t } = 0 in a test requires considerable delicacy.