A single prolate spheroidal element is defined with fibres oriented 65 degrees wrt the horizontal on the inside and -55 degrees wrt the horizontal on the outside. Sheet angles are defined as -45 degrees and +45 degrees at inner and outer nodes respectively. Geometry is interpolated isochorically (Focus^3.Cosh[lambda].Sinh^2[lambda]). Hydrostatic pressure is interpolated quadratically in Xi3 (element based) and the pole-zero law defines the incompressible material behaviour. The prolate is inflated with a pressure of 2kPa on the inside face while the the pressure is held at zero on the outside face.
#Example_5512 Inflation of an orthotropic prolate spheroid with fibres and sheets fem fem define coordinate;r;profib;example #Defines 3 GLOBAL PROLATE SPHEROIDAL # ! coordinates. # ! Transmural interpolation is in # ! Focus^3.Cosh(Lamda).Sinh^2(Lamda). fem define node;r;;example #Focus = 37.5. Reads 4 NODES, 3 COORDS, # ! 1 VERSION per node per nj, 0 # ! DERIVATIVES for all coords. Nodal # ! coordinates, Xj, are (lamda,mu,theta): # ! 1=(0.43,0,0);2=(0.43,120,0); # ! 3=(0.72,0,0); 4=(0.72,120,0). fem define base;r;;example #Defines 3 basis functions: # ! 1) Lagrange/Hermite with 3 Xi coords, # ! Linear Lagrange interpolant and 1 # ! Gauss point in Xi1 dirctn (theta- # ! circumferential) but 3 in Xi2 (mu- # ! longitudinal) and Xi3 (lamda- # ! transmural); # ! 2) An auxiliary basis with 5 auxiliary # ! element parameters, pressure basis # ! same number of Gauss points as for # ! basis function 1, and polynomial # ! degrees of: 0 for Xi1 and Xi2 for # ! all 5 parameters; 0 in Xi3 for # ! parameter 1; 1 for parameter 2; 2 # ! for parameter 3; -1 for parameter # ! 4 (Xi3=0 face pressure bc); & -2 # ! for parameter 5 (Xi3=1 face # ! pressure bc). # ! 3) 2 Xi coords with linear Lagrange # ! interpolant, and 3 Gauss points # ! in Xi1 and Xi2 directions. fem define element;r;;example #Defines 1 prolate spheroidal element. fem define fibre;r;;example #Defines fibre angle orientation wrt Xi1 # ! direction (theta) in degrees. Uses # ! basis 1 for fibre angle interpolation # ! in all elements. No version prompts # ! or derivs. Nodes 1,2 (inner nodes) # ! are oriented at 65 degrees while the # ! outer nodes 3,4 are -55 degrees from # ! the axis. Defines sheet angles of -45 degrees # ! at inner nodes 1,2 and +45 # ! degrees at outer nodes 3,4. fem define element;r;;example fibre #Defines fibre elements. fem define window;r;;example #Defines window dimensions in X,Y,Z # ! directions as (min,max):(-5,5),(-5,5), # ! (-5,5). fem draw lines #Makes line segments visible on window. fem define equation;r;;example #Static 3D finite elasticity problem with # ! geometric coords as the dependent # ! variables. Solution is by Galerkin # ! finite elements in a nonlinear # ! analysis of a nonlinear equation. # ! Incompressible material with basis 1 # ! in all elements for dep vars 1,2,3 # ! and basis 2 in all elements for dep # ! var 4 (hydrostatic pressure). fem define material;r;;example #Stresses in constitutive law are # ! referred to body coords. Defines a # ! hyperelastic constitutive law for # ! which the strain energy function, W, # ! is a function of fibre/transverse # ! strains that is pole-zero in strains # ! with 16 constant constitutive law # ! parameters. The Lagrangian strain # ! components are referred to the # ! undeformed fibre coordinate system # ! where the 1-direction is aligned with # ! fibre axis, 2-direction is the sheet # ! axis (in the plane of the sheet, # ! perpendicular to the fibres), and the # ! 3-direction is the sheet-normal coordinate. fem define initial;r;;example #Boundary pressure increments are entered # ! and hydrostatic pressure is matched # ! across boundaries with adjacent Xi3 # ! faces. Initial displacements are all # ! zero. For dependent variable 2 # ! (mu-dirn) fix all nodes (1..4); # ! Dependent variable 3 (theta-dirn), # ! fix node 2. No force bcs. # ! Dependent variable 4 (hyd press) fix # ! element 1, parameter 4 (Xi3=0 face # ! inside prolate) with increment # ! magnitude 2, and parameter 5 (Xi3=1 # ! face outside prolate) with increment # ! magnitude 0. No force bcs. fem export nodes;heart1 field as heart #export the undeformed nodes fem export elements;heart1 field as heart #export the undeformed elements fem define solve;r;profib;example # Read in solution information. fem solve increment 0.2 iter 3 #Solve the problem. # !Incrementing of the ventricular # ! pressure is neccessary to avoid # ! unstable solutions. This depends on # ! the constitutive law and pressure # ! the constitutive law and pressure # ! magnitude, as the wall is gradually # ! stiffened. fem export nodes;heart2 field as heart #export the deformed nodes fem export elements;heart2 field as heart #export the deformed elements # fem solve increment 0.3 iter 3 fem export nodes;heart3 field as heart fem export elements;heart3 field as heart # fem solve increment 0.5 fem export nodes;heart4 field as heart fem export elements;heart4 field as heart # # # fem draw lines def dotted #Draw deformed mesh on window. fem list strain at 1 ref #List strain information wrt reference # ! coordinates. fem list stress at 1 ref #List stress information wrt reference # ! coordinates. # # # Use the file view.com to view 3d animation in cmgui
fem list stress at 1 ref fem list strain at 1 ref
| Status | Tested | Real time (s) | |
| cmo_irix | Success | Mon May 12 21:09:53 2003 | 1 |
| cmo_linux | Success | Mon May 12 19:06:24 2003 | 1 |
| Success | cmo_irix: | cmiss_test.log.retain. |
| Success | cmo_linux: | cmiss_test.log.retain. |
| Success | cmo_irix: | ndiff test: no significant differences with generic answer. |
| Success | cmo_linux: | ndiff test: no significant differences with generic answer. |
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Input last modified: Tue Dec 17 12:07:58 2002