Search results
Results from the WOW.Com Content Network
Dynamic nanoindentation with continuous stiffness measurement (CSM) Dynamic nanoindentation or continuous stiffness measurement (CSM, also offered commercially as CMX, dynamics...), introduced in 1989, [4] is a significant improvement over the quasi-static mode described above.
Dynamic mechanical analysis (abbreviated DMA) is a technique used to study and characterize materials. It is most useful for studying the viscoelastic behavior of polymers . A sinusoidal stress is applied and the strain in the material is measured, allowing one to determine the complex modulus .
The ratio of the loss modulus to storage modulus in a viscoelastic material is defined as the , (cf. loss tangent), which provides a measure of damping in the material. tan δ {\displaystyle \tan \delta } can also be visualized as the tangent of the phase angle ( δ {\displaystyle \delta } ) between the storage and loss modulus.
The stiffness, , of a body is a measure of the resistance offered by an elastic body to deformation. For an elastic body with a single degree of freedom (DOF) (for example, stretching or compression of a rod), the stiffness is defined as k = F δ {\displaystyle k={\frac {F}{\delta }}} where,
The shear modulus is one of several quantities for measuring the stiffness of materials. All of them arise in the generalized Hooke's law: . Young's modulus E describes the material's strain response to uniaxial stress in the direction of this stress (like pulling on the ends of a wire or putting a weight on top of a column, with the wire getting longer and the column losing height),
Since the Payne effect is essential for the frequency and amplitude-dependent dynamic stiffness and damping behaviour of rubber bushings, automotive tires and other products, constitutive models to represent it have been developed in the past (e.g., Lion et al. 2003). [6]
DFT allows for the calculation of stress tensors which provide a direct measure of the internal pressure. Pressure-volume curve : Plot the applied pressure against the resulting volume change. The bulk modulus can be calculated from the slope of this curve in the linear elastic region.The bulk modulus is defined as K =− VdV / dP , where V is ...
The blades are excited using three mechanical shakers and the response is measured using 12 accelerometers mounted to Blade 3; in the next stage of the test, the accelerometers can be moved to Blade 2 and 3 to measure response at those locations. [1] Modal analysis is the study of the dynamic properties of systems in the frequency domain.