S ep 2 00 3 Junction of elastic plates and beams ( Preliminary version )

We consider the linearized elasticity system in a multidomain of R 3. This multidomain is the union of a horizontal plate with fixed cross section and small thickness ε, and of a vertical beam with fixed height and small cross section of radius r ε. The lateral boundary of the plate and the top of the beam are assumed to be clamped. When ε and r ε tend to zero simultaneously, with r ε ≫ ε 2 , we identify the limit problem. This limit problem involves six junction conditions.