In order to improve design safety of large tonnage non standard hook applied in offshore crane,FEM model was built to calculate structural strength and stress distribution of ITL-2000 four-hook,on the basis of force analysis on hook due to generalized elasticity method for curved beam.Comparing with results achieved by different structure shape,the effect of dimension parameters on maximum stress was also discussed with respect to section shape and horizontal shape.Its influence degree was determined successively.It provides an analysis tool for the optimization design of large hook applied in offshore crane.

In order to improve the design safety and reliability of LeBus grooved drum applied in offshore crane,FEM technology is used to calculate structural strength and deformation of drum barrel and flange,on the basis of force analysis on drum due to the wire rope windings.The currently common calculating method of stability is given.Drum stability is also analyzed in the comprehensive conditions of vertical pressure on drum barrel and horizontal pressure on flange surface.The study provides the analysis tool and reference for the structure optimization design.

In order to improve design safety and reliability on ship-borne loading device, dynamic model of a ship-borne loading device was built based on ADAMS. Wave excitation under 5 and 8 level of sea state were loaded on the condition of limit marine working environment. Kinetic property of ship-borne device was simulated, dynamic behaviors of key parts were also analyzed. Mechanism optimal strategy was proposed and verified by increasing horizontal roller layout and extending gap between horizontal roller and track, providing with an analysis tool for the optimization design of ship-borne device.

In order to improve ship information technology in marine development and manufacture,crane vessel database system is developed based on relational database Access.Effective data can be obtained through ADO and imported in Excel format as well,seamlessly connecting Excel help to input and output offsets information automatically.The database provides with an efficient approach to save and inquire vessel information,improving hull match and reducing development cycle of ship style selection and reconstruction.

Crane arm is an import actuating mechanism of floating crane,which determines whole safety and reliability of the equipment.In order to meet high load requirement of 12000t floating crane in ten thousand class floating crane developing project,the finite element method(FEM) is applied to analyze the structure strength of boom joint on crane arm.Structure design is optimized by increasing boom diameter and thickness,adding support separates in boom box girder respectively.Finally,optimized scheme is achieved with the consideration of both meeting strength requirement and controlling boom weight.

In order to improve efficiency of simulation modeling after scheme generation, a model base of generalized executive mechanisms (GEM) was built based on Simulink. By dividing GEM into executive mechanism and drive component, executive mechanisms library and drive components library were constructed respectively. Model interface of executive mechanism was encapsulated by using mask technology and defining basic parameters as variables. GEM simulation model could be created rapidly by two approaches: searching and applying models for scheme directly; decomposing and combining similar models mannually. Examples of ship-borne device and vibrating screen mechanism illustrate the validity of proposed GEM simulation model base, providing with a modeling tool for GEM simulation analysis.

In order to provide effective method and reliable support for analyzing and forecasting customer requirements on product function,a novel approach is put forward to analyze and forecast importance of product function requirements based on subjective objective synthetic method and combination forecasting model.Customer requirements on product function are classified into basic function,regulating function and interest function in the view of analyzing representation forms of product function in customer requirements from function design standpoint;importance weights of requirement characteristics are determined by analytic hierarchy process,entropy method and mean square difference method;importance weight variation of functional requirements is predicated by using the combination forecasting model built by regression analysis,grey theory and back-propagation neural network.Statistical data of the functional requirements of a certain numerical control milling machine as an example to show the validity and feasibility of the proposed method.

In order to improve design safety and reliability on ship-borne device,dynamic character of a ship-borne device was simulated based on sea state excitation.Wave excitation under 5 and 8 level of sea state were loaded on the condition of limit marine working environment.Kinetic property of ship-borne device was simulated through ADAMS,dynamic behaviors of key parts were also analyzed.Mechanism optimal strategy was proposed and verified by increasing horizontal roller layout and extending gap between horizontal roller and track,providing with an analysis tool for the optimization design of ship-borne device.

In order to analyze representation forms of product function in customer requirements,a novel method is proposed to characterize and analyze production function requirements based on Kano model and fuzzy clustering.Product function from customer requirements is classified into basic function,principal function and surprise function,and their concepts are defined.Scattered requirement characters are categorized based on fuzzy clustering theory,also the detailed steps for the approach are given.Finally,an example of NC milling machine is used to demonstrate the validity of this approach.

Submarine accidents can cause loss of human life and economy, as well as environment damage. Also submarine rescue is difficult for the complexity of rescue process and the uncertainty of the sea state. Success of rescue process is determined by reliability and safety of rescue device. Therefore, research on related device design is rather important. The existing knowledge always supplies some empirical formulas and generates a design scheme by general design rules. The scheme plan obtained may not be a good one due to simplicity of mechanical calculation analysis and particularity of design requirements. To improve design safety and reliability of shipborne device on submarine rescue system, dynamics simulation model of LV-DSRV based on sea state excitation was created in this paper. Wave excitation input at sea state 5 and 8 was considered as the extreme marine working conditions. Kinetic property of LV-DSRV was calculated making use of virtual prototype technology through ADAMS software, and mechanical characteristics of key parts were also analyzed. Optimization strategy was proposed and verified by increasing the number of horizontal wheels and adding gap between horizontal wheels and the track, providing with a case study for similar marine special mechanism design.

Visual simulation is paid more attention as an effective way for evaluation in shipbuilding industry.In order to ensure the reality and reliability of 3D models,models must be converted from CAD into visual simulation efficiently.However,it is hard to realize data seamless transformation because of the different data structure between two systems.Therefore,a novel method of interface technology for the exported Tribon model data and OpenFlight data of visual simulation is presented.In order to satisfy the real-time rendering of visual simulation,multi-resolution LOD model representations are also created by Schroeder triangle mesh simplification algorithm for improving the runtime speed of some developed visual simulation system of ship.The simulation result shows that the system with converted models renders good reality and immersive sense and the interface technology is reasonable and valid.

Real-time simulation of volumetric cloud is an important part for improving fidelity of virtual reality natural environment. However, its peculiar microstructures and intricate volume-filling formation makes cloud simulation more difficult. A novel algorithm for real-time cloud simulation was proposed based on previous work. The algorithm utilizes cellular automaton modeling method to create cloud formation; wind function to simulated cloud motion; single and multiple scattering methods to synthesize cloud illumination; consistency of continuous frame to implement cloud rendering and Murakami meatball to calculate the density distribution of cloud. The results show that this method is efficient and effective in cloud simulation.