How to label the surfaces of a 3D mesh created in gmsh?

General Discussion
1

Hello, ff++ developers and users,

I am currently seeking to perform structural analysis using a 3D mesh created in Gmsh.

I am encountering difficulties as I am unable to label the surfaces that define the boundary conditions.

The execution programme and mesh (Trial_rev.msh) are as follows.

Having researched other queries, I understand that the (.msh) file must be in the ASCII format for ver2.x, so I have adhered to this requirement.

// Structural analysis 
//		based on linear elasticity constitutive law

verbosity = 2;

//  Loading optional items
load "medit" 	// for data save
load "iovtk"	// for data save in vtk
load "msh3"
load "gmsh"

//  parameters
real E;			E 			= 1.0;						// Young's modulus	
real nu; 		nu 			= 0.3;						// Poisson's ratio
real lambda;	lambda 		= nu*1./(1+nu)/(1-2.*nu);	// Lame coefficient
real mu; 		mu 			= 1./2./(1+nu);				// Lame coefficient

//  geometry and Mesh
mesh3 Th = gmshload3("Trial_rev.msh");
plot(Th, cmm="Trial_rev mesh");

<Trial_rev.msh>

$MeshFormat
2.2 0 8
$EndMeshFormat
$PhysicalNames
3
2 5 "1"
2 6 "2"
3 4 "1"
$EndPhysicalNames
$ParametricNodes
11
1 0 0.4 0.6 0 1
2 0.4 0.6 0.4 0 2
3 0.2 0.5 0.5 0 3
4 0.2 0.4 0.3 0 4
5 0.2 0.5 0.7 0 5
6 0.001305110561923167 0.3864015091027275 0.5708453523625702 1 1 0.2878640269841284
7 0.1570451406175511 0.3772810889250968 0.318994466923867 1 1 0.5582303286262873
8 0.3746531103139279 0.5648889642322492 0.3677982629936062 1 1 0.8192566879424583
9 0.001305110561923167 0.3864015091027275 0.7708453523625701 1 3 0.2878640269841284
10 0.1570451406175511 0.3772810889250968 0.518994466923867 1 3 0.5582303286262873
11 0.3746531103139279 0.5648889642322492 0.5677982629936064 1 3 0.8192566879424583
$EndParametricNodes
$Elements
32
1 15 2 0 1 1
2 15 2 0 2 2
3 15 2 0 3 3
4 15 2 0 4 4
5 15 2 0 5 5
6 1 2 0 1 3 6
7 1 2 0 1 6 7
8 1 2 0 1 7 8
9 1 2 0 1 8 3
10 1 2 0 2 3 5
11 1 2 0 3 5 9
12 1 2 0 3 9 10
13 1 2 0 3 10 11
14 1 2 0 3 11 5
15 2 2 0 1 7 3 6
16 2 2 0 1 8 3 7
17 2 2 0 2 5 3 9
18 2 2 0 2 11 3 5
19 2 2 0 2 3 6 9
20 2 2 0 2 8 3 11
21 2 2 0 2 6 7 10
22 2 2 0 2 9 6 10
23 2 2 0 2 10 7 8
24 2 2 0 2 10 8 11
25 2 2 0 3 10 5 9
26 2 2 0 3 11 5 10
27 4 2 0 1 8 10 11 3
28 4 2 0 1 3 9 10 5
29 4 2 0 1 7 10 8 3
30 4 2 0 1 5 11 10 3
31 4 2 0 1 10 7 6 3
32 4 2 0 1 9 3 10 6
$EndElements

message when programm is run

 PhysicalNames is not considered in freefem++
 ParametricNodes is not considered yet in freefem++