the shear modulus, where G is the shear modulus is the solid's density. Shear modulus of metals The shear modulus of metals is usually observed to decrease with increasing temperature. At high pressures, the shear modulus also appears to increase with the applied pressure. Correlations between the melting temperature, vacancy formation energy, and the shear modulus have been observed in many metals. Several models exist that attempt to predict the shear modulus of metals (and possibly that of alloys). Shear modulus models that have been used in plastic flow computations include: the MTS shear modulus model developed by and used in conjunction with the Mechanical Threshold Stress (MTS) plastic flow stress model. the Steinberg-Cochran-Guinan (SCG) shear modulus model developed by and used in conjunction with the Steinberg-Cochran-Guinan-Lund (SCGL) flow stress model. the Nadal and LePoac (NP) shear modulus model that uses Lindemann theory to determine the temperature dependence and the SCG model for pressure dependence of the shear modulus. MTS model The MTS shear modulus model has the form: where is the shear modulus at , and and are material constants. SCG model The Steinberg-Cochran-Guinan (SCG) shear modulus model is pressure dependent and has the form where, μ0 is the shear modulus at the reference state (T = 300 K, p = 0, η = 1), p is the pressure, and T is the temperature. NP model The Nadal-Le Poac (NP) shear modulus model is a modified version of the SCG model. The empirical temperature dependence of the shear modulus in the SCG model is replaced with an equation based on Lindemann melting theory. The NP shear modulus model has the form: where and μ0 is the shear modulus at absolute zero and ambient pressure, ζ is a area, m is the atomic mass, and f is the Lindemann constant. Shear relaxation modulus The shear relaxation modulus is the time-dependent generalization of the shear modulus : . See also Elasticity tensor Dynamic modulus Impulse excitation technique Shear strength Seismic moment References Materials science Elasticity (physics)