6. Material deformation and exponential behaviors Creep is a thermally activated process by which materials undergo...
6. Material deformation and exponential behaviors Creep is a thermally activated process by which materials undergo slow, permanent, deformation. It is described by the following equation: = Ce-oc/RT, also written as. E = exp(-RT) where έ is the creep rate, C is a pre-exponential constant determined experimentally, Q. is the activation or threshold energy required for the process to occur, R is the universal gas constant, an T is absolute temperature. To experimentally determine Cand Q. for a particular material, creep rates (, and éz) are measured at two di simultaneous exponential equations: Use the two exponential equations to algebraically find an expression for Q determined from the two known creep rates and the two known temperatures (note you have two equations with two unknowns, C and Q). Do this using the following two methods: Method 1: Start by dividing the two exponential equations, then solve for Qe Note the C's cancel in the division of the two equations. Method 2: Start by transforming the equations into the y mx+ b form by taking the natural logarithm of both sides, then adding or subtracting one equation from the other. Note this will eliminate C as an unknown in your equations.
6. Material deformation and exponential behaviors Creep is a thermally activated process by which materials undergo slow, permanent, deformation. It is described by the following equation: = Ce-oc/RT, also written as. E = exp(-RT) where έ is the creep rate, C is a pre-exponential constant determined experimentally, Q. is the activation or threshold energy required for the process to occur, R is the universal gas constant, an T is absolute temperature. To experimentally determine Cand Q. for a particular material, creep rates (, and éz) are measured at two di simultaneous exponential equations: Use the two exponential equations to algebraically find an expression for Q determined from the two known creep rates and the two known temperatures (note you have two equations with two unknowns, C and Q). Do this using the following two methods: Method 1: Start by dividing the two exponential equations, then solve for Qe Note the C's cancel in the division of the two equations. Method 2: Start by transforming the equations into the y mx+ b form by taking the natural logarithm of both sides, then adding or subtracting one equation from the other. Note this will eliminate C as an unknown in your equations.