Sea Rescue Boats Extension Ladder Design And Analysis

With the social and economic development, maritime activities are more and more frequent. And shipwrecks sometimes occur inevitably. Compare to other kinds of rescue, sea rescue, which is taken in complex circumstance and requires timeliness, has its particular characteristics. But it will facilitate the sea rescue if a telescopic rescue ladder with simply operated and quickly extended was applied. By using this kind of rescue ladder, which can stand certain load, the success rate of rescue operation will be improved. The casualties and property losses will be reduced.According the characteristic of sea rescue job, the design was achieved, referencing in some rescue ladders applied in other situation and some normal telescopic mechanism. This design is particularly aimed to rescue ship. The bearing beams of telescopic rescue ladder are based on standard channel steel. And the extension action of ladder is directed by a driven system which contains one set of hydraulic system and one set of pulley block. The rise and fall action that is indispensable when the ladder is operated. This action is driven by another set of hydraulic system. The modeling work was completed by the three dimension design software UG NX6.0 to describe the design. Also the motion analysis was conducted through the motion simulation module of UG to check the rationality of design when in motion and to propose improvements for further modification. Stress analysis and calculation on bearing beam was executed to obtain the optimal parameters on the premise of design requirements. Basing on the bearing beams, the detail design of other parts of ladder were involved. When the detail design finished, the finite element analysis attaches to important parts of telescopic ladder was conducted by ANSYS workbench to check the mechanical properties, and to find some necessary modification.First, the initial design was constructed by the design requirement and relative mechanical theory. Then it was expressed by three-dimensional model set up through UG NX 6.0. But the dimension of each part was undefined.The ladder model which was assembled in UG, was analyzed through UG motion simulate module. The rationality of structure was checked when the model being simulated. The modification was conducted when problems were found.Then according to the structure of telescopic ladder, analyze the stress characteristic of bearing beams to find the stress law. The mathematical model of bearing beam was summed up through the law. And then the optimal model can be set up basing on design requirement and initial condition. So the optimal design parameters were obtained after the optimization computation. Then according to optimal result, detail design involves in bearing beams was taken with considering of dimensional coordination between beams. The dimensional parameters of other parts were defined directly or indirectly by the bearing beams.Finally, the finite element analysis of parts was carried out to check the responsibility of rescue ladder. Some further modifications were also executed in the case of some unreasonable factors were found from analysis result. The bearing beams were firstly analyzed by the FEA software ANSYS workbench, then the base system and stand system. The discussion of each part also presented when analysis finished.