5.1.3 Spatially varying element properties

Product: ABAQUS/Standard  

Features tested

This section demonstrates the use of distributions and element property assignments to model spatially varying element properties.

I. Using distributions and element property assignments to define thicknesses, offsets, material orientations, and stiffness matrices for shell elements

Elements tested

S3R    STRI3    S4    S4R    S4R5    STRI65    S8R    S8R5    S9R5   

SC6R    SC8R   

SAX1    SAX2    SAXA   

Problem description

The analyses in this section demonstrate how distributions and element property assignments can be used to define spatially varying element properties in shells. The geometry in each test is a flat plate modeled with either 9 quadrilateral shell elements or 18 triangular shell elements. In most test cases each shell element is assigned a different thickness, offset, and material orientation using distributions. In some cases both distributions and nodal thicknesses are used to define the shell thicknesses. A linear elastic orthotropic material is used in each case. All the test cases in this section were verified by creating equivalent reference models using multiple section assignments to define the shell thicknesses, offsets, and material properties. Some of these reference models are included.

Loading:

The multistep analysis performed on each model consists of the following:

  • Step 1: A frequency analysis.

  • Step 2: A steady-state dynamic analysis with modal damping and nodal loads.

  • Step 3: A modal dynamic analysis with modal damping and nodal loads.

  • Step 4: A direct steady-state dynamic analysis with modal damping and nodal loads.

  • Step 5: A subspace projection steady-state dynamic analysis with nodal loads.

  • Step 6: A random response analysis with nodal loads.

  • Step 7: A response spectrum analysis.

  • Step 8: A geometrically nonlinear static analysis with displacement boundary conditions.

  • Step 9: A load case static analysis using distributed body loads, gravity loads, and centrifugal loads.

Results and discussion

The results for each model agree with the associated reference solutions.

Input files

distrib_multistep_s3r_gs_std.inp

Multistep analysis using S3R elements and a general shell section definition. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_s3r_nt_gs_std.inp

Multistep analysis using S3R elements, a general shell section definition, and nodal thicknesses. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_s3r_std.inp

Multistep analysis using S3R elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_s3r_nt_std.inp

Multistep analysis using S3R elements with a shell section definition that is integrated during the analysis and nodal thicknesses. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_s4_gs_std.inp

Multistep analysis using S4 elements and a general shell section. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_s4_gs_ref_std.inp

Reference solution for distrib_multistep_s4_gs_std.inp using multiple shell section definitions to define varying shell thicknesses, offsets, and material orientations.

distrib_multistep_s4_nt_gs_std.inp

Multistep analysis using S4 elements, a general shell section definition, and nodal thicknesses. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_s4_std.inp

Multistep analysis using S4 elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_s4_rs_std.inp

Restart analysis for distrib_multistep_s4_std.inp.

distrib_multistep_s4_nt_std.inp

Multistep analysis using S4 elements with a shell section definition that is integrated during the analysis and nodal thicknesses. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_s4_nt_ref_std.inp

Reference solution for distrib_multistep_s4_nt_std.inp using multiple shell section definitions and nodal thicknesses to define varying shell thicknesses, offsets, and material orientations.

distrib_multistep_s4_nt1_gs_std.inp

Multistep analysis using S4 elements, a general shell section definition, and nodal thicknesses. Distributions and element property assignments are used to modify offsets and material orientations.

distrib_multistep_s4_nt1_std.inp

Multistep analysis using S4 elements with a shell section definition that is integrated during the analysis and nodal thicknesses. Distributions and element property assignments are used to modify offsets and material orientations.

distrib_multistep_s4_st_std.inp

Multistep analysis using S4 elements with a general shell section definition. The section stiffness is specified directly. Distributions and element property assignments are used to modify shell section stiffness and material orientations. The distributions for the section stiffnesses and material orientations are read from separate input files distrib_s4_stiff_in.inp and distrib_s4_orient_in.inp.

distrib_s4_stiff_in.inp

Input file for section stiffness distribution for distrib_multistep_s4_st_std.inp.

distrib_s4_orient_in.inp

Input file for material orientation distribution for distrib_multistep_s4_st_std.inp.

distrib_multistep_s4r_gs_std.inp

Multistep analysis using S4R elements and a general shell section definition. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_s4r_std.inp

Multistep analysis using S4R elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_s4r_hyp_std.inp

Multistep analysis using S4R elements with a shell section definition that is integrated during the analysis and a hyperelastic material. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_s4r5_gs_std.inp

Multistep analysis using S4R5 elements and a general shell section definition. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_s4r5_std.inp

Multistep analysis using S4R5 elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_s8r_gs_std.inp

Multistep analysis using S8R elements and a general shell section definition. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_s8r_std.inp

Multistep analysis using S8R elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_s8r5_gs_std.inp

Multistep analysis using S8R5 elements and a general shell section definition. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_s8r5_std.inp

Multistep analysis using S8R5 elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_s9r5_gs_std.inp

Multistep analysis using S9R5 elements and a general shell section definition. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_s9r5_std.inp

Multistep analysis using S9R5 elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_sc6r_gs_std.inp

Multistep analysis using SC6R elements and a general shell section definition. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_sc6r_std.inp

Multistep analysis using SC6R elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_sc8r_gs_std.inp

Multistep analysis using SC8R elements and a general shell section definition. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_sc8r_std.inp

Multistep analysis using SC8R elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_stri3_gs_std.inp

Multistep analysis using STRI3 elements and a general shell section definition. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_stri3_std.inp

Multistep analysis using STRI3 elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_stri65_gs_std.inp

Multistep analysis using STRI65 elements and a general shell section definition. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_stri65_std.inp

Multistep analysis using STRI65 elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_sax1_std.inp

Multistep analysis using SAX1 elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify shell thicknesses and offsets.

distrib_multistep_sax2_std.inp

Multistep analysis using SAX2 elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify shell thicknesses and offsets.

distrib_multistep_sax2t_std.inp

Multistep analysis using SAX2T elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify shell thicknesses and offsets.

distrib_multistep_saxa12_std.inp

Multistep analysis using SAXA12 elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

distrib_multistep_saxa22_std.inp

Multistep analysis using SAXA22 elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

II. Using distributions and element property assignments to define material orientations for continuum elements

Elements tested

CPS3    CPE3    CPS4    CPS4R    CPE4    CPE4H    CPE4I    CPE4R   

CPS6    CPS6M    CPE6    CPE6M    CPS8    CPS8R    CPE8    CPE8R   

CAX3    CAX4    CAX4H    CAX4I    CAX4R    CAX6    CAX6M    CAX8    CAX8R   

CGAX3    CGAX4    CGAX4H    CGAX4R    CGAX6    CGAX6M    CGAX8    CGAX8R   

C3D4    C3D6    C3D8    C3D10    C3D10M    C3D15    C3D20   

Problem description

The analyses in this section demonstrate how distributions and element property assignments can be used to define material orientations on an element-by-element basis for continuum elements. The geometry in two-dimensional tests is a unit square modeled with either 9 quadrilateral or 18 triangular elements. The geometry in the three-dimensional tests is a unit cube with between 8 to 12 elements. In most test cases each solid element is assigned a different material orientation using a distribution. All the test cases in this section were verified by creating equivalent reference models using multiple section assignments to define material orientations. Some of these reference models are included. In some cases the residual mode functionality is also tested.

Loading:

The multistep analysis performed on each model consists of the following:

  • Step 1: A frequency analysis.

  • Step 2: A steady-state dynamic analysis with modal damping and nodal loads.

  • Step 3: A modal dynamic analysis with modal damping and nodal loads.

  • Step 4: A direct steady-state dynamic analysis with modal damping and nodal loads.

  • Step 5: A subspace projection steady-state dynamic analysis with nodal loads.

  • Step 6: A random response analysis with nodal loads.

  • Step 7: A response spectrum analysis.

  • Step 8: A geometrically nonlinear static analysis with displacement boundary conditions.

  • Step 9: A load case static analysis using distributed body loads, gravity loads, and centrifugal loads.

For cases in which the residual mode functionality is tested, a static perturbation step is added prior to the frequency step.

Results and discussion

The results for each model agree with the associated reference solutions.

Input files

distrib_multistep_c3d4_std.inp

Multistep analysis using C3D4 elements. Distributions and element property assignments are used to modify material orientations. In addition, residual modes are activated in the frequency step for use in the subsequent modal procedures.

distrib_multistep_c3d6_std.inp

Multistep analysis using C3D6 elements. Distributions and element property assignments are used to modify material orientations. In addition, residual modes are activated in the frequency step for use in the subsequent modal procedures.

distrib_multistep_c3d8_std.inp

Multistep analysis using C3D8 elements. Distributions and element property assignments are used to modify material orientations. In addition, residual modes are activated in the frequency step for use in the subsequent modal procedures.

distrib_multistep_c3d10_std.inp

Multistep analysis using C3D10 elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_c3d10_ref_std.inp

Reference solution for distrib_multistep_c3d10_std.inp using multiple solid section definitions to define varying material orientations.

distrib_multistep_c3d10m_std.inp

Multistep analysis using C3D10M elements. Distributions and element property assignments are used to modify material orientations. In addition, residual modes are activated in the frequency step for use in the subsequent modal procedures.

distrib_multistep_c3d15_std.inp

Multistep analysis using C3D15 elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_c3d20r_std.inp

Multistep analysis using C3D20R elements. Distributions and element property assignments are used to modify material orientations. In addition, residual modes are activated in the frequency step for use in the subsequent modal procedures.

distrib_multistep_cax3_std.inp

Multistep analysis using CAX3 elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cax4_std.inp

Multistep analysis using CAX4 elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cax4h_std.inp

Multistep analysis using CAX4H elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cax4i_std.inp

Multistep analysis using CAX4I elements. Distributions and element property assignments are used to modify material orientations. In addition, residual modes are activated in the frequency step for use in the subsequent modal procedures.

distrib_multistep_cax4r_std.inp

Multistep analysis using CAX4R elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cax6_std.inp

Multistep analysis using CAX6 elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cax6m_std.inp

Multistep analysis using CAX6M elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cax8_std.inp

Multistep analysis using CAX8 elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cax8r_std.inp

Multistep analysis using CAX8R elements. Distributions and element property assignments are used to modify material orientations. In addition, residual modes are activated in the frequency step for use in the subsequent modal procedures.

distrib_multistep_cgax3_std.inp

Multistep analysis using CGAX3 elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cgax4_std.inp

Multistep analysis using CGAX4 elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cgax4h_std.inp

Multistep analysis using CGAX4H elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cgax4r_std.inp

Multistep analysis using CGAX4R elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cgax6_std.inp

Multistep analysis using CGAX6 elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cgax8_std.inp

Multistep analysis using CGAX8 elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cgax8r_std.inp

Multistep analysis using CGAX8R elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cpe3_std.inp

Multistep analysis using CPE3 elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cpe4_std.inp

Multistep analysis using CPE4 elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cpe4h_std.inp

Multistep analysis using CPE4H elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cpe4i_std.inp

Multistep analysis using CPE4I elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cpe4r_std.inp

Multistep analysis using CPE4R elements. Distributions and element property assignments are used to modify material orientations. In addition, residual modes are activated in the frequency step for use in the subsequent modal procedures.

distrib_multistep_cpe6_std.inp

Multistep analysis using CPE6 elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cpe6m_std.inp

Multistep analysis using CPE6M elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cpe8_std.inp

Multistep analysis using CPE8 elements. Distributions and element property assignments are used to modify material orientations. In addition, residual modes are activated in the frequency step for use in the subsequent modal procedures.

distrib_multistep_cpe8_ref_std.inp

Reference solution for distrib_multistep_cpe8_std.inp using multiple solid section definitions to define varying material orientations.

distrib_multistep_cpe8r_std.inp

Multistep analysis using CPE8R elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cps3_std.inp

Multistep analysis using CPS3 elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cps4_std.inp

Multistep analysis using CPS4 elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cps4r_std.inp

Multistep analysis using CPS4R elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cps6_std.inp

Multistep analysis using CPS6 elements. Distributions and element property assignments are used to modify material orientations. In addition, residual modes are activated in the frequency step for use in the subsequent modal procedures.

distrib_multistep_cps6m_std.inp

Multistep analysis using CPS6M elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cps8_std.inp

Multistep analysis using CPS8 elements. Distributions and element property assignments are used to modify material orientations.

distrib_multistep_cps8r_std.inp

Multistep analysis using CPS8R elements. Distributions and element property assignments are used to modify material orientations. In addition, residual modes are activated in the frequency step for use in the subsequent modal procedures.

III. Using distributions and element property assignments while transferring results from one ABAQUS/Standard analysis to another

Elements tested

S3R    S4R    SAX1   

CPE4    C3D8   

Problem description

The analyses in this section demonstrate that element properties defined with an element property assignment can be transferred from one ABAQUS/Standard analysis to another. All the test cases in this section were verified by creating equivalent reference models using multiple section assignments to define the shell thicknesses, offsets, and material properties. Some of these reference models are included.

Results and discussion

The results for each model agree with the associated reference solutions.

Input files

ss1_s3r_ep.inp

Two geometrically nonlinear static steps using S3R elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

ss2_s3r_ep_n_n.inp

Imports both elements in ss1_s3r_ep.inp at the end of Step 1 with UPDATE=NO and STATE=NO. One new S3R element is defined.

ss2_s3r_ep_n_y.inp

Imports both elements in ss1_s3r_ep.inp at the end of Step 1 with UPDATE=NO and STATE=YES. One new S3R element is defined.

ss2_s3r_ep_y_n.inp

Imports both elements in ss1_s3r_ep.inp at the end of Step 1 with UPDATE=YES and STATE=NO. One new S3R element is defined.

ss2_s3r_ep_y_y.inp

Imports both elements in ss1_s3r_ep.inp at the end of Step 1 with UPDATE=YES and STATE=YES. One new S3R element is defined.

ss1_s4r_ep.inp

Two geometrically nonlinear static steps using S4R elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

ss2_s4r_ep_n_n.inp

Imports both elements in ss1_s4r_ep.inp at the end of Step 1 with UPDATE=NO and STATE=NO. One new S4R element is defined.

ss2_s4r_ep_n_y.inp

Imports both elements in ss1_s4r_ep.inp at the end of Step 1 with UPDATE=NO and STATE=YES. One new S4R element is defined.

ss2_s4r_ep_y_n.inp

Imports both elements in ss1_s4r_ep.inp at the end of Step 1 with UPDATE=YES and STATE=NO. One new S4R element is defined.

ss2_s4r_ep_y_y.inp

Imports both elements in ss1_s4r_ep.inp at the end of Step 1 with UPDATE=YES and STATE=YES. One new S4R element is defined.

ss1_s4r_ep_ref.inp

Reference solution for ss1_s4r_ep.inp using multiple shell section definitions to define varying shell thicknesses, offsets, and material orientations.

ss2_s4r_ep_ref_n_n.inp

Reference solution for ss2_s4r_ep_n_n.inp.

ss2_s4r_ep_ref_n_y.inp

Reference solution for ss2_s4r_ep_n_y.inp.

ss2_s4r_ep_ref_y_n.inp

Reference solution for ss2_s4r_ep_y_n.inp.

ss2_s4r_ep_ref_y_y.inp

Reference solution for ss2_s4r_ep_y_y.inp.

ss1_s4r_ep_gs.inp

Two geometrically nonlinear static steps using S4R elements with a general shell section definition. Distributions and element property assignments are used to modify shell thicknesses, offsets, and material orientations.

ss2_s4r_ep_gs_n_n.inp

Imports both elements in ss1_s4r_ep_gs.inp at the end of Step 1 with UPDATE=NO and STATE=NO. One new S4R element is defined.

ss2_s4r_ep_gs_n_y.inp

Imports both elements in ss1_s4r_ep_gs.inp at the end of Step 1 with UPDATE=NO and STATE=YES. One new S4R element is defined.

ss2_s4r_ep_gs_y_n.inp

Imports both elements in ss1_s4r_ep_gs.inp at the end of Step 1 with UPDATE=YES and STATE=NO. One new S4R element is defined.

ss2_s4r_ep_gs_y_y.inp

Imports both elements in ss1_s4r_ep_gs.inp at the end of Step 1 with UPDATE=YES and STATE=YES. One new S4R element is defined.

ss1_s4r_ep_gs_st.inp

Two geometrically nonlinear static steps using S4R elements with a general shell section definition. The section stiffness is specified directly. Distributions and element property assignments are used to modify shell section stiffness and material orientations.

ss2_s4r_ep_gs_st_n_n.inp

Imports both elements in ss1_s4r_ep_gs_st.inp at the end of Step 1 with UPDATE=NO and STATE=NO. One new S4R element is defined.

ss2_s4r_ep_gs_st_n_y.inp

Imports both elements in ss1_s4r_ep_gs_st.inp at the end of Step 1 with UPDATE=NO and STATE=YES. One new S4R element is defined.

ss2_s4r_ep_gs_st_y_n.inp

Imports both elements in ss1_s4r_ep_gs_st.inp at the end of Step 1 with UPDATE=YES and STATE=NO. One new S4R element is defined.

ss2_s4r_ep_gs_st_y_y.inp

Imports both elements in ss1_s4r_ep_gs_st.inp at the end of Step 1 with UPDATE=YES and STATE=YES. One new S4R element is defined.

ss1_sax1_ep.inp

Two geometrically nonlinear static steps using SAX1 elements with a shell section definition that is integrated during the analysis. Distributions and element property assignments are used to modify shell thicknesses and offsets.

ss2_sax1_ep_n_n.inp

Imports both elements in ss1_sax1_ep.inp at the end of Step 1 with UPDATE=NO and STATE=NO. One new SAX1 element is defined.

ss2_sax1_ep_n_y.inp

Imports both elements in ss1_sax1_ep.inp at the end of Step 1 with UPDATE=NO and STATE=YES. One new SAX1 element is defined.

ss2_sax1_ep_y_n.inp

Imports both elements in ss1_sax1_ep.inp at the end of Step 1 with UPDATE=YES and STATE=NO. One new SAX1 element is defined.

ss2_sax1_ep_y_y.inp

Imports both elements in ss1_sax1_ep.inp at the end of Step 1 with UPDATE=YES and STATE=YES. One new SAX1 element is defined.

ss1_sax1_ep_ref.inp

Reference solution for ss1_sax1_ep.inp using multiple shell section definitions to define varying shell thicknesses and offsets.

ss2_sax1_ep_ref_n_n.inp

Reference solution for ss2_sax1_ep_n_n.inp.

ss2_sax1_ep_ref_n_y.inp

Reference solution for ss2_sax1_ep_n_y.inp.

ss2_sax1_ep_ref_y_n.inp

Reference solution for ss2_sax1_ep_y_n.inp.

ss2_sax1_ep_ref_y_y.inp

Reference solution for ss2_sax1_ep_y_y.inp.