What is meant by constitutive relation?
In physics and engineering, a constitutive equation or constitutive relation is a relation between two physical quantities (especially kinetic quantities as related to kinematic quantities) that is specific to a material or substance, and approximates the response of that material to external stimuli, usually as …
What are the constitutive relations and their significance?
A constitutive relation approximates the observed physical behavior of a material under specific conditions of interest. To summarize, constitutive relations are required for two reasons: To bring in the material dependence in the force displacement relation.
What are constitutive models?
Constitutive models describe the material responses to different mechanical and/or thermal loading conditions, which provide the stress–strain relations to formulate the governing equations, together with the conservation laws and kinematic relations.
How many constitutive equations are there?
BME 456: Constitutive Equations: Elasticity. We have 12 equations of which 9 are independent, and 21 unknowns, of which there are 15 independent unknowns after accounting for symmetry: 6 stresses, 6 strains, and 3 displacements.
What does constitutively mean in biology?
Refers to genes that are transcribed in an ongoing manner, with control limited to that directly associated with the metabolic state of the organism. Constitutively expressed genes, that is, are always “on”. Contrast inducible as well as repressible or, indeed, facultative genes. …
What is the order of constitutive tensor Cijkl?
Cijkl is a fourth order tensor known as stiffness tensor. In the remaining section we will call it as stiffness matrix, as popularly known. The individual elements of this tensor are the stiffness coefficients for this linear stress-strain relationship.
What is a mechanical constitutive equation?
constitutive equation in Mechanical Engineering A constitutive equation is an equation that describes the relationship between two physical quantities, for example between the stress put on a material and the strain produced on it. The constitutive equation for most metals is based on Hooke’s law.
What is constitutive model of communication?
Instead of portraying communication as merely the transmission of information, the constitutive model posits that communication has power to shape reality itself (Baxter & Montgomery, 1996). In contrast, the constitutive model argues the relationship exists because of the communication that takes place within it.
What is strain formula?
The strain formula is: S = \frac{\Delta x}{X} Here, S = strain (it is unitless) \Delta x = change in dimension. X = original dimension.
What are compatibility equations?
The compatibility equation (1.88) for the nonsymmetric deformation of shallow caps were given in Chapter I. This equation reveals the connection between the membrane stress function F(r, ϕ) and the changes of the Gaussian curvature in the initial and deformed state Γ − Γ ¯ .
What is an example of a constitutive gene?
Constitutive genes are those that are always active. Genes for ribosomes are an example. They are constantly being transcribed because ribosomes are constantly needed for protein synthesis. For example, the glucose transporter proteins that muscle cells produce in response to insulin are the product of inducible genes.
What is an example of constitutive expression?
Expression of a gene that is transcribed at a constant level. For example, the expression of housekeeping genes to produce proteins such as actin, GAPDH and ubiquitin.