strainandstressutilitiesmodule Module Reference

Module with utility subroutines for strain- and stress calculation. More...

Functions/Subroutines
subroutine	principlestrains2d (epsC, eps1, eps2, gamma, alpha1, alphaGamma)
	Calculation of principal strains in 2D. More...
subroutine	principlestresses2d (sigC, sig1, sig2, tau, alpha1, alphaTau)
	Calculation of principal stresses in 2D. More...
subroutine	straindispcst (nndof, xEl, yEl, zEl, T_el, zPos, B_el)
	Computes strain-displacement matrix for constant strain triangle. More...
subroutine	straindispquad4 (nndof, xEl, yEl, zEl, T_el, xi, eta, zPos, B_el)
	Computes strain-displacement matrix for the 4-noded quadrilateral. More...
real(dp) function, dimension(3)	getglobalizedx (eZ)
	Calculates the X-axis direction of the globalized coordinate system. More...
subroutine	getshellelementaxes (nenod, X, Y, Z, V1, V2, V3, lpu, ierr, doGlobalize)
	Computes the local element axes for a thin shell element. More...
subroutine	getshellstresstrans (eX, eZ, T, lpu, ierr)
	Computes the stress transformation matrix for a thin shell element. More...

Detailed Description

Module with utility subroutines for strain- and stress calculation.

Function/Subroutine Documentation

getglobalizedx()

real(dp) function, dimension(3) strainandstressutilitiesmodule::getglobalizedx

(

real(dp), dimension(3), intent(in)

eZ

)

Calculates the X-axis direction of the globalized coordinate system.

Parameters

[in]

eZ

Local Z-axis (normal vector) of the shell surface

Returns

Globalized X-axis direction vector for the shell surface

This function computes the vector V1 defined by the projection of the global X-axis onto the plane defined by the normal vector eZ.

Author

Knut Morten Okstad

Date

30 Nov 2000

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getshellelementaxes()

subroutine strainandstressutilitiesmodule::getshellelementaxes	(	integer, intent(in)	nenod,
		real(dp), dimension(nenod), intent(in)	X,
		real(dp), dimension(nenod), intent(in)	Y,
		real(dp), dimension(nenod), intent(in)	Z,
		real(dp), dimension(3), intent(out)	V1,
		real(dp), dimension(3), intent(out)	V2,
		real(dp), dimension(3), intent(out)	V3,
		integer, intent(in)	lpu,
		integer, intent(out)	ierr,
		logical, optional	doGlobalize
	)

Computes the local element axes for a thin shell element.

Parameters

[in]	nenod	Number of element nodes (3 or 4)
[in]	X	Global X-coordinates for the element
[in]	Y	Global Y-coordinates for the element
[in]	Z	Global Z-coordinates for the element
[out]	V1	Direction of local X-axis for the element
[out]	V2	Direction of local Y-axis for the element
[out]	V3	Direction of local Z-axis for the element
[in]	lpu	File unit number for res-file output
[out]	ierr	Error flag
[in]	doGlobalize	If .true., the globalized shell axes are computed

The local-to-global transformation matrix is then T = [V1,V2,V3]. Optionally, the globalized shell element axes can be computed instead of the local element axes.

Author

Knut Morten Okstad

Date

30 Nov 2000

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getshellstresstrans()

subroutine strainandstressutilitiesmodule::getshellstresstrans	(	real(dp), dimension(3), intent(in)	eX,
		real(dp), dimension(3), intent(in)	eZ,
		real(dp), dimension(2,2), intent(out)	T,
		integer, intent(in)	lpu,
		integer, intent(out)	ierr
	)

Computes the stress transformation matrix for a thin shell element.

Parameters

[in]	eX	X-axis of the element coordinate system
[in]	eZ	Z-axis of the element coordinate system
[out]	T	In-plane transformation matrix
[in]	lpu	File unit number for res-file output
[out]	ierr	Error flag

This subroutine computes the 2D transformation matrix from the element coordinate system to the continuous stress output coordinate system for a shell element.

Author

Knut Morten Okstad

Date

30 Nov 2000

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principlestrains2d()

subroutine strainandstressutilitiesmodule::principlestrains2d	(	real(dp), dimension(3), intent(in)	epsC,
		real(dp), intent(out)	eps1,
		real(dp), intent(out)	eps2,
		real(dp), intent(out)	gamma,
		real(dp), intent(out), optional	alpha1,
		real(dp), intent(out), optional	alphaGamma
	)

Calculation of principal strains in 2D.

Parameters

[in]	epsC	Strain components
[out]	eps1	Maximum principal strain
[out]	eps2	Minimum principal strain
[out]	gamma	Maximum shear strain
[out]	alpha1	Angle between local X-axis and direction of eps1
[out]	alphaGamma	Angle between local X-axis and direction of gamma

This subroutine computes the principle strains, max shear strain, angle to the (max) principle strain and angle to the max shear strain. Using Mohr's circle interpretation.

Note

The shear strain epsC(3) is assumed to be the quantity γ_xy = ε_xy + ε_yx where ε_xy = ε_yx is the tensorial shear strain component.

Author

Bjorn Haugen

Date

13 Apr 2000

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principlestresses2d()

subroutine strainandstressutilitiesmodule::principlestresses2d	(	real(dp), dimension(3), intent(in)	sigC,
		real(dp), intent(out)	sig1,
		real(dp), intent(out)	sig2,
		real(dp), intent(out)	tau,
		real(dp), intent(out), optional	alpha1,
		real(dp), intent(out), optional	alphaTau
	)

Calculation of principal stresses in 2D.

Parameters

[in]	sigC	Stress components
[out]	sig1	Maximum principal stress
[out]	sig2	Minimum principal stress
[out]	tau	Maximum shear stress
[out]	alpha1	Angle between local X-axis and direction of sig1
[out]	alphaTau	Angle between local X-axis and direction of tau

This subroutine computes the principle stresses, max shear stress, angle to the (max) principle stress and angle to the max shear stress. Using Mohr's circle interpretation.

Author

Bjorn Haugen

Date

13 Apr 2000

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straindispcst()

subroutine strainandstressutilitiesmodule::straindispcst	(	integer, intent(in)	nndof,
		real(dp), dimension(:), intent(in)	xEl,
		real(dp), dimension(:), intent(in)	yEl,
		real(dp), dimension(:), intent(in)	zEl,
		real(dp), dimension(3,3), intent(in)	T_el,
		real(dp), intent(in)	zPos,
		real(dp), dimension(3,nndof,3), intent(out)	B_el
	)

Computes strain-displacement matrix for constant strain triangle.

Parameters

[in]	nndof	Number of DOFs per nodal point
[in]	xEl	X-coordinates of the element nodes
[in]	yEl	Y-coordinates of the element nodes
[in]	zEl	Z-coordinates of the element nodes
[in]	T_el	Global-to-local transformation matrix for the element
[in]	zPos	Local position of top shell surface w.r.t. the mid-surface
[out]	B_el	Strain-displacement matrix for the element

Author

Bjorn Haugen

Date

13 Apr 2000

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straindispquad4()

subroutine strainandstressutilitiesmodule::straindispquad4	(	integer, intent(in)	nndof,
		real(dp), dimension(:), intent(in)	xEl,
		real(dp), dimension(:), intent(in)	yEl,
		real(dp), dimension(:), intent(in)	zEl,
		real(dp), dimension(3,3), intent(in)	T_el,
		real(dp), intent(in)	xi,
		real(dp), intent(in)	eta,
		real(dp), intent(in)	zPos,
		real(dp), dimension(3,nndof,4), intent(out)	B_el
	)

Computes strain-displacement matrix for the 4-noded quadrilateral.

Parameters

[in]	nndof	Number of DOFs per nodal point
[in]	xEl	X-coordinates of the element nodes
[in]	yEl	Y-coordinates of the element nodes
[in]	zEl	Z-coordinates of the element nodes
[in]	T_el	Global-to-local transformation matrix for the element
[in]	xi	First coordinate in domain [-1,1] of evaluation point
[in]	eta	Second coordinate in domain [-1,1] of evaluation point
[in]	zPos	Local position of top shell surface w.r.t. the mid-surface
[out]	B_el	Strain-displacement matrix for the element

Author

Bjorn Haugen

Date

13 Apr 2000

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