Research On Assembly Process Model Of Hull Structure And Application Of Man-hours Calculation

With the rapid development of global science and technology and economy in recent years,shipbuilding industry has gradually transited from the traditional mechanical plant to the digital plant and intelligent plant,and introduced information and intelligent technology in production design,assembly design,precision detection and other aspects.At the same time of technological progress,the competition of enterprises is increasingly fierce,especially the requirements of manufacturing cycle and production cost are increasingly strict.In the shipbuilding industry,the assembly process generally takes the longest time and consumes the most resources,while in the hull assembly,the subsection assembly takes about half of the total assembly time.Therefore,it will save cost and reduce manufacturing cycle to control the subsection assembly process,promote the subsection assembly process and evaluate the assembly plan.Assembly process and scheme are usually expressed in the form of assembly sequence,so the research of reasonable assembly sequence planning can effectively achieve the purpose of promoting production and shortening manufacturing cycle.However,through the literature review and learning,we find that there are some shortcomings in the assembly sequence planning method.In order to solve the problems of assembly sequence planning,such as unclear judgment of assembly and welding process between different assembly bodies,ambiguous determination of each process,and inaccurate calculation of assembly time for each component and each station,this thesis studies the assembly process model and puts forward the calculation method of assembly time based on the assembly model.Different from other complex assemblies,the hull segments are large in volume and weight,and most of them are built by assembly as the basic unit of hull segments.Each middle / small group has its own construction site.After the completion of several group construction,the group will form a group in the group construction site,and after the completion of the group,the group will form a hull section in the large group construction site.At the same time,there are strict requirements for the construction of moulding bed,and the requirements for moulding bed corresponding to each datum plane are quite different.Moreover,the selection of the construction datum will limit the quality and efficiency of the subsequent installationpositioning and welding process,which forms the most significant difference between the hull segment and other complex assemblies.Based on the analysis of hull assembly process and technology,and combined with assembly time,the research object of this thesis is determined: the key process from group assembly to large assembly;the key factors of hull section assembly are found out,and the assembly process model is established;the traditional assembly sequence is not clear about assembly logic and assembly relationship,and so on The expression meaning of assembly sequence is added,and the discrimination conditions of assembly division and selection of assembly datum plane are added,so that it can adapt to the hull section;for different assembly schemes,a calculation method model is established,which takes the discrimination of assembly mode,welding mode and installation positioning mode as the core,so as to achieve the accurate judgment of each assembly process step.Finally,the assembly time is calculated according to the efficiency of each assembly process.In this thesis,by analyzing the segmented model and data of an example,an effective assembly information database is established,and the information extraction and the automation of the calculation method are realized by using MATLAB editing calculation method,which proves the feasibility of the calculation method.For the known hull segment and the given assembly sequence,it can quickly identify the assembly methods and means used in each assembly link of the assembly route,and determine the working hours consumed by each station,which provides a theoretical basis for more convenient evaluation of assembly scheme,so as to achieve the purpose of saving the production cost of the ship.