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feynman1
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Consider a simple shear x=kY, y=Y, z=Z. How is Poynting effect defined? If the normal stress along y is 0 but that along x isn't 0, is that also a sort of Poynting effect?
No, but about shear and the corresponding normal stressesChestermiller said:You're talking about the effect of pressure on the Gibbs free energy?
I have no idea what you are referring to. Are you asking about the components of the stress tensor for the shear deformation you defined?feynman1 said:No, but about shear and the corresponding normal stresses
Yes, the normal and shear stress components, that is discussion about the normal components when shear is present.Chestermiller said:I have no idea what you are referring to. Are you asking about the components of the stress tensor for the shear deformation you defined?
OK. Are you familiar with the 3D tensorial version of Hooke's Law? If so, for this particular deformation, what does that predict for the components of the strain and stress tensors?feynman1 said:Yes, the normal and shear stress components, that is discussion about the normal components when shear is present.
Yes and I did the analysis, just wonder the precise definition of the effectChestermiller said:OK. Are you familiar with the 3D tensorial version of Hooke's Law? If so, for this particular deformation, what does that predict for the components of the strain and stress tensors?
Precise definition of what effect?feynman1 said:Yes and I did the analysis, just wonder the precise definition of the effect
poyntingChestermiller said:Precise definition of what effect?
right, but that's just a description not a rigorous definition. Does poynting refer to nonzero normal stresses or one specific normal stress component?Chestermiller said:In large deformations (even shear), the stress tensor is not just a linear function of the strain tensor, however that is defined (there are many tensorially acceptable definitions for finite strains). It is a non-linear function of the strain tensor, and this non-linearity results in not only shear stresses, but also normal stresses that are functions of the amount of shear (in simple shear).
For the deformation described in this thread, the state of stress is not isotropic, and all three normal stresses are non-zero.feynman1 said:right, but that's just a description not a rigorous definition. Does poynting refer to nonzero normal stresses or one specific normal stress component?
So if only one of sigma_x and sigma_y is 0, will that be called poyning effect?Chestermiller said:For the deformation described in this thread, the state of stress is not isotropic, and all three normal stresses are non-zero.
What it is specifically called does not matter (to me). What matters is whether such an effect exists.feynman1 said:So if only one of sigma_x and sigma_y is 0, will that be called poyning effect?
agree, but that will affect assessment and comparison with the literature when not knowing if the same thing is discussedChestermiller said:What it is specifically called does not matter (to me). What matters is whether such an effect exists.
The Poynting effect for simple shear is a phenomenon in physics that describes the transfer of energy from an electromagnetic field to a material under shear stress. It is named after John Henry Poynting, a British physicist who first described the effect in the late 19th century.
The Poynting effect for simple shear occurs when an electromagnetic field is applied to a material that is under shear stress, causing the energy from the field to be transferred to the material. This results in a change in the material's properties, such as its electrical conductivity or magnetic susceptibility.
The Poynting effect for simple shear has various applications in fields such as materials science, electromagnetism, and geophysics. It is used to study the behavior and properties of different materials under shear stress, as well as to understand the effects of electromagnetic fields on these materials.
The Poynting effect for simple shear is different from other forms of the Poynting effect, such as the Poynting vector or Poynting's theorem, in that it specifically describes the transfer of energy from an electromagnetic field to a material under shear stress. Other forms of the Poynting effect may describe the overall energy flow in an electromagnetic system.
Examples of the Poynting effect for simple shear can be found in various materials and systems, such as in the behavior of rocks under tectonic stress, the response of metal alloys to magnetic fields, and the effects of shear stress on the electrical properties of polymers. It is also relevant in understanding the behavior of materials in industrial processes, such as metal forming and welding.