Problem Description

In this example a curved cantilever beam, modeled with shell elements, is subjected to unit forces at the tip in the in-plane and out-of-plane directions, that is, the Y and Z directions, respectively. The in-plane and out-of-plane loads are applied in different load cases. The tip displacements in the direction of the load are compared with independent hand calculated results.
The geometry, properties and loading are as suggested in MacNeal and Harder 1985. The cantilever beam is bent into a 90° arc. It has a 4.12 inch inner radius and a 4.32 inch outer radius. Thus it is 0.2 inch wide and approximately 6.63 inch long at its centerline. The beam is 0.1 inch thick in the Y direction. For modeling in this model, the curved beam is meshed into six area objects, each subtending a 15° arc.

Tested Features

Membrane analysis using shell elements
Plate bending analysis using shell elements
Joint force loading

App

Object Link: https://openbrim.org/objidyvjfs1i4x6jt71lko8u0f.project

Library

Object Link: https://openbrim.org/objiddykgrci7chnb70o0soybcn.libobj

Thin Plate Option and Thick Plate Option DOC-92 - Getting issue details... STATUS

Model and Mesh	Load Case and Type	Output Parameter	OpenBrIM	SAP2000	Independent	Percent Difference (SAP2000 vs Independent)	Percent Difference (OpenBrIM vs Independent)
Model A 6x1 mesh	Load case IN In-Plane	Uy, in Average of jts 7 and 14	0.0818	0.0773	0.0886	-13%	0%
Model B 90x1 mesh	$0.0830$	0.0845	-5%	0%
Model C 90x3 mesh	0.0879	0.0884	0%	0%
Model D 6x1 mesh with each of 6 objects submeshed 15x3	0.0887	0.0893	1%	0%

Model and Mesh

Load Case and Type

Output Parameter

OpenBrIM

SAP2000

Independent

Percent Difference

(SAP2000 vs Independent)

Percent Difference

(OpenBrIM vs Independent)

Model A

6x1 mesh

Load case IN In-Plane

Uy, in Average of jts 7 and 14

0.0818

0.0773

0.0886

-13%

Model B

90x1 mesh

0.0830

0.0845

-5%

Model C

90x3 mesh

0.0879

0.0884

Model D

6x1 mesh with each of 6 objects submeshed 15x3

0.0887

0.0893

Thick Plate Option

Model and Mesh	Load Case and Type	Output Parameter	OpenBrIM	SAP2000	Independent	Percent Difference (SAP2000 vs Independent)	Percent Difference (OpenBrIM vs Independent)
Model A 6x1 mesh	Load case OUT Out-of-Plane	Uz, in Average of jts 7 and 14	0.4518	0.4298	0.5004 (0.4546)	-14% (-5%)	-9% (0%)
Model B 90x1 mesh	0.4511	0.4566	-9% (0%)	-9% (0%)
Model C 90x3 mesh	0.4509	0.4558	-9% (0%)	-9% (0%)
Model D 6x1 mesh with each of 6 objects submeshed 15x3	0.4524	0.4570	-9% (1%)	-9% (0%)

Model and Mesh

Load Case and Type

Output Parameter

OpenBrIM

SAP2000

Independent

Percent Difference

(SAP2000 vs Independent)

Percent Difference

(OpenBrIM vs Independent)

Model A

6x1 mesh

Load case OUT Out-of-Plane

Uz, in Average of jts 7 and 14

0.4518

0.4298

0.5004

(0.4546)

-14%

(-5%)

-9%

(0%)

Model B

90x1 mesh

0.4511

0.4566

-9%

(0%)

-9%

(0%)

Model C

90x3 mesh

0.4509

0.4558

-9%

(0%)

-9%

(0%)

Model D

6x1 mesh with each of 6 objects submeshed 15x3

0.4524

0.4570

-9%

(1%)

-9%

(0%)