L.B.Lerman
Effect of weak shock waves on elastic barriers with design discontinuities

Acoustic bulletin, Vol. 2 3, (1999) p.60-68
The boundary problem on non-steady acoustoelasticity for laminated shielding designs, stiffened by a system of beam supports is solved. Considered mechanical system is dismembered on separate units, motions of which are described with appropriate differential equations. The unknown forces of interaction of elastic units are determined from the additional conditions of joint deformation Slices and support. The surface loads are determined from conditions of continuous contact at joint motion of a barrier and media. The indicated conditions are written as the systems of functional equations. Representation of desired functions, loads and responses as the series on vectorial functions circumscribing the eigenmodes of separate components of system including gas volumes allows to reduce the functional equations to infinite system of Volterra's integro-differential equations. Obtained system is solved numerically by sequential iterations, and on everyone step of mentioned procedure the system of equations of a dynamic contact problem is solved. For particular values of the parameters of a problem the characteristics of stress-strained state of system components at effect of stepwise weak shock waves are determined. It was established, that the effect of the medium appears at reaching already the first extremums, and becomes more vivid for deflections and their velocities, than for deformations and their velocities. It was found that as the intensity of a statical load is accepted equal to pressure jump at the front of waves, the maximum dynamic factor appears to be close to 4. The above factor depends on flexural stiffness of the plate.
KEY WORDS:
weak shock wave, fencing structure, dynamic factor
TEXT LANGUAGE: Russian