Selected aspects of simulation of multi - module mechanisms with the use of multibody method

The paper presents numerical analysis of a single segment of a floating bridge built in the form of a metal cassette with a movable bottom. An internal elastic container - a pontoon filled with the air was fixed in the cassette [4]. It enables a fluent change of displacement of a single segment and of a floating ribbon assembled from segments. A multibody analysis of cooperation of the cassette in the process of filling the pontoon and opening the cassette was discussed. Numerical analysis of a single cassette presented in the paper constitutes a part of tests including stand tests. The single floating cassette has a typical shelled construction consists of a tight deck, a pneumatic chamber closed with a reinforced movable bottom and sets of fastenings together with a mechanism of bottom opening. Each cassette is equipped with a highly resistant elastic or semi-elastic cushion hereinafter called a pontoon. The movement of the bottom and the process of opening the cassette module with a pneumatic air cushion realized under an influence of pressure of the compressed air. As a result of uneven filling the individual chamber of the pontoon with the air or their uneven emptying in the process of closing the cassette, there can occur the asymmetry of displacements of the bottom resulted even in seizing of telescopic mechanisms. In the paper were considered the cases of symmetrical and asymmetrical movement of the bottom corresponding to symmetrical and unsymmetrical pull out of the telescopic mechanism modules. Dynamical analysis of movement of cooperating subsystems of the floating cassette was carried out with the use of MSC.Adams code [5, 8].