Search

In this article, according to the reliability appraisal of the structure of a heavy industrial plant which is near service limit years, we found several major safety hazard issues and proposed corrective measures to reinforce. On the basis of structural calculation and analysis, we could determine whether to upgrade the crane and propose the corresponding feasibility upgrade project, which can provide the basis for other similar identification.

The paper proposes a particle pair optimization (PPO) algorithm for numerical optimization. In the paper, a particle pair search(PPS) is designed. Based on PPS, the competitive roulette strategy is employed to the selection of particle pair from swarm, and a particle pair optimization algorithm is proposed. In the experiments, PPO is applied to solve the 12 benchmark problem, and compared with fast evolutionary programming (FEP). The results demonstrate that PPO algorithm can find optima or close-to-optimal solutions of the complex functions with high-dimension, and the search of PPO is stable and efficient.

New-style ketchup packaging composite board box is an important technical innovation in ketchup packaging and has broad market prospect because of its economic and recyclable. Some tests including material property test and assembly property test have been done on the new-style composite board box. Different thickness boards such as 20mm, 25mm and 28mm have been tested in the paper. The results show that new-style composite board box can meet the requirements of ketchup packing.

Finite element method has been used to analysis the stress of inner pipes of low temperature storage tank for LNG caused by temperature, pressure and weight. Filling liquid state, storing liquid state and unloading liquid state are considered in this paper. The results show that the stress of the top pipes would be the largest under filling liquid state which is only little larger than storing liquid state. The stress of the bottom pipes would be the largest under storing liquid state. The deformation of the inner container of the tank would influence the stress distribution. Choosing a flexible structure as designing the bottom pipes is reasonable.

Friction-type high-strength bolt connectors are widely used in steel structure. However there has only general description for connection plate surface treatment method in the current Chinese design standards. Some research tests have been designed for different connection plate surface treatment method, which include different painting thickness and different blasting method. The results show that different treatment method has different anti-sliding coefficient. The anti-sliding coefficient would decrease with the surface coating thickness increase. The anti-sliding coefficient would less than 0.50 which the Chinese design standard required when some surface treatment methods are used, such as using steel wire section or using mixture of steel wire section and steel shot to sand blasting. So procedure qualification test is necessary to guide processing in order to ensure the quality of the products. It has certain conference value for practical engineering.

The design analysis of vertical lathe auxiliary equipment for large pressure vessel processing has been done in this paper. The finite element method has been used to find the main factors which influence the processing precision. The results show that the main factor influencing maximum displacement of overall structure is not the vertical lathe cutting force but the weight of the large pressure vessel. So it is unreasonable to control the processing precision by the whole structure maximum displacement. The horizontal displacement is the main factor in controlling processing precision. The pressure vessel work piece sits on the top plate of the vertical lathe auxiliary equipment. So the displacement of the top plate of the vertical lathe auxiliary equipment is the main factor influencing processing precision. This kind of design thinking has been successfully applied in three type large pressure vessels. It has certain reference value in similar design.