Dear Dave Diehl,thanks your reply.
I'll try yours and Richard's suggestion.
I think we can input the max stiffness snubber,and we select this snubber according the stiffness,so the snubber can support more load than the result of analysis.For example,if we input the stiffness as 0.2E+8 N./cm , the result of dynamic analysis is 10000N,but the max allowable load of snubber(corresponding 0.2E+8 N./cm) is 1000000N.When we design the support,we select the snubber according to its stiffness 0.2E+8 N./cm,and we design the structure according the result load 10000N.Maybe there are some mistake,but I can not find out,would you please tell me where is wrong?