For our graduate mini project v are designing a bike with curved frame(please see the line diagram from the link).how can we take the distribution of load along the structure to design the curved frame which is a hollow tube and the forks of the bike??? http://www.hostpic.org/view.php?filename=13untitled.bmp

I think the best way would be to model the frame and mesh it using FEA software (ansys, nastran, hypermesh, ...), then apply the loads, boundary conditions and material properties to run a stress analysis. This would give you the stress distribution on the frame and hinges. You could then alter the design to obtain a better distribution. Also, I know Hypermesh has a optimizing function that allows you to obtain the best geometry for the predetermined loads, available space, etc. This geometry can be obtained depending on various optimisation criteria such as minimizing weight, minimizing highest stress, ... I'm sure you can also calculate the stress by hand but I can't help you with that as I only know how to do beam calculations with straight sections.