I don't think Davor's suggestion is quite what Anoop is looking for - that would just represent the static weight of the component resting on the chosen point. An impact analysis is going to require an energy component (m × g × h).
If the impact is assumed to be taken on a single, fixed point then a starting point would be first analyse the part with a unit force to estimate the linear stiffness, then work out the force required to convert the gravitational energy into spring energy (m g h = 1/2 k x^2). By scaling the stress results of your initial analysis you can then estimate whether this force is enough to cause the material to yield or break.
A more complex analysis than that will probably require contact and non-linear materials - I don't even know whether a full time-domain impact analysis is possible in Mechanica, but hopefully one of the experts will be along shortly to tell us!
