how to define the shape of a heavy duty chain link when the pitch of the chain and the traction load that the chain is subjected to is known? lets say i consider the traction load as the maximum load the chain can support, how can i do the back calculation from that to find the required dimensions?
Assuming you have the load on the Conveyor belt and dynamic load factor, usually from 3 to 10, let's call that load Ft.
The pitch of a chain is the distance between two bushings in mm.
Ft is supported by shear stress in the pin and is 0.6 times the tensile strength.
You decide what steel alloy you use and calculate the surface area of the pin that is adequate to take the Ft, from there you have the diameter.
There are many types of chains and depending on the task same are better. the following is a quote from a handbook of design based on ISO standard. I added the link to the handbook at the end of my answer.
Block chains have a high tensile strength for a reduced width. They are used to convey heavy loads, abrasive loads or when violent shocks are expected (e.g.: draw benches). To increase the service life of the chain (better wear resistance), the blocks are sometimes bushed.