Li Yaner

On March 26, Lei Fanpei, chairman of CSSC, visited Dassault Group and held a talk with Dassault Group CEO Shabera. During the period, a photo presented by CSSC was remarkable --this was the scene of China's largescale beacon vessel launched at Jiangnan Shipyard (Group) Co., Ltd. Under CSSC on March 22 this year. In the photo, half of the hull is in reality and the other half is a 3D model, “The First Ship Born With Digital Twin Concept” is the best annotation to the cool gift.

On the world first ship born with digital twin concept, Jiangnan Shipyard adopts Dassault's 3D experience platform to realize the construction of full ship large-scale 3D design deliverables(3D “drawings”), which realizes the 3D application of whole process，whole specialty and all elements. From introduction of software to secondary development, from process reformation to promotion of real ship projects, Jiangnan Shipyard, a “century-old shop”,foresees the future of the industry through digital shipbuilding.

Design: Adhere to a Single Digital Model

The digital twin concept is widely applied in the shipbuilding industry,colloquially, the holographic construction of ships in the real world in the computer world, what the real world is like is stored in the computer world. Using the 3D experience platform for digital shipbuilding, Jiangnan Shipyard has set up a benchmark in the whole industry.

At the end of 2015, Jiangnan Shipyard officially introduced the 3D experience platform. Although the platform has mature cases in other industries, and foreign shipyards apply it to some links of ship construction,how to make good use of the platform to make it adapt to the characteristics of ship construction giant system, highly customized and so on, in line with the shipyard construction process, fully tap the potential of the platform? In recent years, Jiangnan Shipyard has been solving this problem.

“The application of the 3D experience platform to the current level is inseparable from the strong decisions of the company's leadership,” Li Haibo, application project manager of the 3D experience platform of Jiangnan Research Institute, was deeply moved.In order to make the platform better fit to Jiangnan Shipyard, the leading team of the company took the lead in maintaining close communication with Dassault. The project team and Dassault R&D department interacted frequently. In almost eight-month design cycle of the large beacon vessel, the project team carried out a lot of secondary development, data verification, professional coordination and system evaluation, and the information technology research institute independently developed more than 200 customization functions in five major specialties -- hull, machinery,electricity, outfitting, interior decoration,providing a solid foundation for the fullprocess and full-element application of the 3D experience platform on the beacon vessel.

In fact, only a year ago, Jiangnan Shipyard was feeling embarrassed about constantly shifting between twodimensional drawings and 3D models in the design and manufacturing process. At that time, the situation was that there was a huge amount of repetitive workload,there were differences in understanding,and it was difficult to guarantee the consistency of the data. As a result, the design and site personnel use experience was very poor.

“In order to change the situation,we consolidated the idea that we had been adhering to -- single digital model.” Sun Changfeng, designer of Jiangnan Research Institute, said that on large beacon vessel, the project personnel built models of point, line and surface; presented the complete solid model and holographic industrial model in the stage of production design; in the manufacturing stage, generated 3D deliverables, 3D task instructions. “We keep adding information to the model.The 3D model is like a 3D drawing, and information flows in every field.”

In the early stage of the project,designers were most worried about the lack of access to high-quality and efficient information on the production site. Therefore, Jiangnan Shipyard reconstructed each professional process,overcoming the bottlenecks such as model synchronization, piecewise modeling,definition assembly instructions, NC package, parts process modeling and information output. Skin expansion of outer plate is one of the major technical problems.

Skin expansion is a construction link, the expansion way of the 3D experience platform does not match the steel plate hot working characteristics in the shipbuilding industry. The algorithm in the industry, both inside and outside the industry, was so closely guarded that it was like a “black box” for a long time. Jiangnan Shipyard, relying on its own strength, consulted numerous documents at home and abroad, and after more than 1000 technical schemes were tried and verified, the project team completed the expansion of 350 outer plates in 8 categories, thus ensuring the application of the 3D experience platform to the large-scale beacon vessel.

Construction: Much Simpler Than Expected

Since the project is the first ship, it is the first time in the shipyard to apply the three drawings to the production site for the first time, and the general construction engineer of the large-scale navigation mark ship, Zhou Xuekun,said, At the beginning of the project, he made sufficient psychological construction and prepared to fight a hard battle. In fact,the ship's construction was smoother going than expected.

The 3D model has become the common language between design and manufacture. “Intuitive!” is the evaluation of the 3D model by most on-site production personnel. Bidding farewell to the thick, big and hard-tounderstand 2Ddrawing, one Pad and notebook can provide all production information including part number,location, material, process, and work step, greatly reducing the time of drawing circulation, identification, analysis and check; the clearer 3D perspective and view can assist and guide the workers in site operation. The designer, the production staff and the management staff are finally able to unify the language exchange and speak in the model. “The shipowner, the classification society also give generous support, the surveyor soon adapts to the changes brought by the new model, and the efficiency of the ship survey is further improved,” said Yuan Kai, chief quality inspector of large-scale beacon vessels.

"The production sector worked together, and the workers were well adapted, especially to the group production stage, and the benefits of the 3D drawings were all felt,”said Zhou Xuekun, masterbuilder of large-scale beacon vessels. One indicator showing smooth progress of the project was a significant reduction in the order change quantity. Xu Pengfei, chief technologies of large-scale beacon vessels, said the total accumulated order changes of the five major disciplines of the beacon vessel were not more than 500, and the error rate of the beacon vessel in the pre-outfitting stage was also slashed, taking into account the factor that the total material amount of the ship was less, and the order changes were about 40% of the same type of ship.

The drastic reduction of order changes was accompanied by a significant increase in the progress of the project. According to the experience of shipbuilding for more than a decade,Zhou Xuekun reserved a three-month embarkation cycle for the ship, but the actual embarkation duration was only 31 days. "The slashing of time on building berth could not do without hard work of the workers, and the new solution and the new model based on the 3D experience platform also play an important role.”

“I think the 3D experience platform application is very successful on the beacon vessel under close cooperation of each department and each discipline.Facts speak louder than words, the software is viable in the shipbuilding industry, and we are more confident in the digital shipbuilding!"Xu Pengfei said.

According to statistics, the number of order changes for large beacon vessel accounted for 12% of general drawings,of which only 9 were orders for 3D experience platform, accounting for 2%. Compared with the same material amount ship type, the order changes of the large beacon vessel is reduced by 40%, the error rate is reduced by 60%,the embarkation cycle is shortened by 67%, and the construction efficiency is improved by 30%.

The beacon vessel is an important product with cross-times significance.With the further promotion and improvement of the 3D experience platform in Jiangnan Shipyard, our efficiency will go up to a few more levels!” Zhou Xuekun said.