  We present dynamical effects on conformation in a simple bead-spring model
consisting of three beads connected by two stiff springs. The conformation
defined by the bending angle between the two springs is determined not only by
a given potential energy function depending on the bending angle, but also fast
motion of the springs which constructs the effective potential. A conformation
corresponding with a local minimum of the effective potential is hence called
the dynamically induced conformation. We develop a theory to derive the
effective potential by using multiple-scale analysis and the averaging method.
A remarkable consequence is that the effective potential depends on the excited
normal modes of the springs and amount of the spring energy. Efficiency of the
obtained effective potential is numerically verified.
