Incorporating bolt stiffness in a resultant spring coefficient calculation for a rigid brace

I’m working on a brace to increase the natural frequency of a verticle pump motor outside of its operational frequency zone. I have some members in potential bending and in compression and I can find their equivalent ‘k’ values and sum them, but there are a number of bolted joints that I can ignore in my summation, but I’m also aware of bolt stiffness. Does this need to be incorporated into my equivalent ‘k’ value for the brace?