STEP Neutral File Lightweight Processing And Model Reconstruction Technology

The close combination of modern industry and information technology has led the manufacturing industry to a digital era.In the process of product production and manufacturing,the wide application of computer aided design(CAX)technology has changed the original design habits of enterprises and designers,so that the design,virtual manufacturing and digital prototype of the whole product can be completed in the computer,bringing a qualitative leap to the design and manufacturing level and production capacity of enterprises.But it also brings new problems.Nowadays,the difficulty of data interaction between heterogeneous CAX systems has become an urgent problem to be solved.The Standard for the Exchange of Product Model Data provides a neutral exchange mechanism for product data interaction that does not depend on a specific system.This paper presents a lightweight design scheme for ship outfitting model based on STEP standard AP227 factory space layout protocol.How to realize the lightweight processing and model reconstruction of AP227 steelwork outfitting model while keeping the original model assembly data and external contour unchanged is the focus of this paper.The basic content and structure of STEP standard and AP227 protocol are studied.The geometric modeling method for defining mechanical equipment in AP227 was studied.Combined with the data characteristics of EXPRESS modeling language,the data mapping from EXPRESS modeling language to C++ is established.The data extraction system of AP227 model is established based on C language.The STEP file of a block fitting-out model is taken as an example for data extraction and the data extraction information file is generated at the same time.Finally,combined with the application of SQL Server database model data information does not rely on computer permanent archiving.Based on the demand analysis of AP227 model lightweight and the characteristics of product model information,a lightweight design scheme for AP227 steelwork outfitting model is proposed.Lightweight the AP227 model while keeping assembly data and external contour unchanged,while hiding internal design information.Feature recognition technology based on attribute adjacency graph is used to extract model features.Based on the model feature suppression technology,the steelwork outfitting model is analyzed,and a series of algorithms are designed to complete the lightweight processing processes of AP227 model,such as component suppression,surface feature processing and Hollowing.The ship outfitting model is split to obtain lightweight component model shelling.Finally,the lightweight AP227 steelwork outfitting assembly model is generated.The lightweight processing system of AP227 steelwork outfitting is developed by using Open GL visualization technology in Visual C++ environment.System tool interface is very simple and intuitive,sub-module gradually completed the realization of each part of the function.Finally,the feasibility and efficiency of the proposed lightweight scheme are verified by multiple steelwork outfitting model.