try NUMERGE option in APDL

first mesh both surfaces separately after that create component for each meshed surfaces from component manager --pic all nodes 

run NUMERGE  and select both components nodes

It will definitely work 

note that this command works on your meshing topology

Before you apply some kind of load you can either try the

NUMMRG,ALL

command and then the dupliocated keypoints,lines, areas and surfaces will be merged.

If this is not desired then selecet the nodes of the above surface and the nodes of the lower surface by the NSEL command (or give a name to your nodes by the CM command).Then apply the NUMMRG,ALL

After that you can use the NUMCMP command to restart the numbering of nodes and elements from 1

I think you should try

VGLUE

before meshing.

NUMMRG,ALL  should solve it.

Hi,

You can try with AADD command. Note :The areas must be coplanar. The original areas (and their corresponding lines and keypoints) will be deleted by default.

use tool-merege

If you want to attach these two parts then use "VGLUE" (In GUI, Modeling>Operate>Booleans) option for volume operation using both GUI or code.

If you want to use some frictional parameters between the common surfaces of the volumes then look at the "Contact Pair" option(In GUI, Modeling>Create).

I think this will solve others problem although very late for yours.

Mahabubur Rahman Hi, say if I wanted to mesh a cylinder, I feel like it is easier to mesh an 90 degree arc instead of a full cylinder, can I actually form 4 parts and glue it then only meshing it, yet assuming it to be a solid body?

@pang, I think if you go for 2D then try designing in asymmetric, you can look in few YouTube videos for that.

for 3D, you should be able to mesh easily and that will depend on your element selection. There are few videos on YouTube for that type of geometry.

I wish I can help but I need more specific description of your problem. Thank you.