scholarly journals A FAST assembly simulation analysis method for hull blocks with engineering constraints

2021 ◽  
pp. 1-24
Author(s):  
Guan Guan ◽  
Hongling Liao ◽  
Qu Yang

In order to effectively improve the assembly efficiency for hull blocks, an assembly simulation analysis method considering engineering constraints is proposed in this paper, and an integrated system of shipbuilding accuracy analysis and assembly analysis considering multi-constraints is developed. The method is divided into pre-matching model and fine matching model. In the pre-matching model, an Improved Coherent Point Drift (ICPD) algorithm is used to obtain more accurate initial matching values. The fine matching model firstly uses the Analytic Hierarchy Process (AHP) algorithm to automatically obtain the constrained weights, then the weights vector is used to add the assembly constraints for hull blocks such as straightness, hard point constraints etc. into the multi-objective optimization function. By solving the function, the optimum positioning location and the most reasonable adjustment scheme are obtained. This method shortens the occupancy time of the equipment used to build the hull, reduces the workload of the staff, and improves the efficiency and quality of shipbuilding. The integrated system adds engineering constraints analysis module and the function of automatically finding and eliminating error measurement points. Through the verification of the examples, the integrated system realizes the automation and intellectualization of the assembly for hull blocks.

2020 ◽  
Vol 36 (02) ◽  
pp. 105-114
Author(s):  
Guan Guan ◽  
Hongling Liao

A point set analysis method considering the practical engineering constraints has been proposed in this article. First, the coherent point drift method was used to obtain the initial values of data analysis. Second, the error distribution in different directions was expressed by weight vectors. Last, the multiobjective optimization model was built and the engineering constrains were introduced into the multioptimization objective function to achieve the optimal data analysis results. The experimental results proved that the method could obtain the reasonable data analysis results, which met the engineering constraints. It provides the important basis for the subsequent assembly.


2012 ◽  
Vol 40 (1) ◽  
pp. 25-41 ◽  
Author(s):  
H. M. R. Aboutorabi ◽  
L. Kung

Abstract REFERENCE: H. M. R. Aboutorabi and L. Kung, “Application of Coupled Structural Acoustic Analysis and Sensitivity Calculations to a Tire Noise Problem,” Tire Science and Technology, TSTCA, Vol. 40, No. 1, January – March 2012, pp. 25–41. ABSTRACT: Tire qualification for an original equipment (OE) program consists of several rounds of submissions by the tire manufacturer for evaluation by the vehicle manufacturer. Tires are evaluated both subjectively, where the tire performance is rated by an expert driver, and objectively, where sensors and testing instruments are used to measure the tire performance. At the end of each round of testing the evaluation results are shared and requirements for performance improvement for the next round are communicated with the tire manufacturer. As building and testing is both expensive and time consuming predictive modeling and simulation analysis that can be applied to the performance of the tire is of great interest and value. This paper presents an application of finite element analysis (FEA) modeling along with experimental verification to solve tire noise objections at certain frequencies raised by an original equipment manufacturer (OEM) account. Coupled structural-acoustic analysis method was used to find modal characteristics of the tire at the objectionable frequencies. Sensitivity calculations were then carried out to evaluate the strength of contribution from each tire component to the identified modes. Based on these findings changes to the construction were proposed and implemented that addressed the noise issue.


Author(s):  
G. Marimuthu ◽  
G. Ramesh

Decisions usually involve the getting the best solution, selecting the suitable experiments, most appropriate judgments, taking the quality results etc., using some techniques.  Every decision making can be considered as the choice from the set of alternatives based on a set of criteria.  The fuzzy analytic hierarchy process is a multi-criteria decision making and is dealing with decision making problems through pairwise comparisons mode [10].  The weight vectors from this comparison model are obtained by using extent analysis method.  This paper concern with an alternate method of finding the weight vectors from the original fuzzy AHP decision model (moderate fuzzy AHP model), that has the same rank as obtained in original fuzzy AHP and ideal fuzzy AHP decision models.


2016 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Antonius Dwi Yunianto, Santun R. P. Sitorus, dan Khursatul Munibah

The provision of Green Open Space (GOS) constitutes an important need for city and as a mandate ofthe Law on Spatial Planning. Ungaran city currently has the width of public GOS under 20%. It makesUngaran city has not yet qualified to become a Green City. The objectives of this study are to identify andanalyze the width and distribution of GOS existing condition; to analyze the needs of Ungaran’s GOSin order to meet the specified conditions of prevailing law; to arrange the plan of GOS based on GreenPlanning concept; and to arrange the design of GOS based on Green Design concept. The analysis willbe conducted by using Patch Analysis method. The analysis of GOS is based on the inhabitant’s needand the wide area, and the Analytic Hierarchy Process (AHP). The GOS mapping result of Ungarancity is 2.190,66 ha which consists of private GOS (2.112,74 ha) and public GOS (77,92 ha). Based onthe total projection of population in 2032, the public GOS need is 292,41 ha. Whereas the needs ofpublic GOS based on the 20% from wide area (612,17 ha). The direction of public GOS developmentbased on green planning is divided into three alternatives, first, based on the balance distribution ofGOS within the area, and land use priority; second, based on the balance distribution of GOS, land usepriority, distance to the residence, minimum width of 250m2, and the complexity of landform; third,based on the consideration of the spatial patterns and regional asset authority. The direction of publicGOS development is based on green design approach to divide the design based on necessity activityand function patterns of public GOS.


2019 ◽  
Vol 9 (4) ◽  
pp. 744 ◽  
Author(s):  
Zhiqiang Wu ◽  
Hui Ma ◽  
Chi Wang ◽  
Jinhui Li ◽  
Jun Zhu

Prodders are widely used devices in landmine detection. A sensorized prodder has been developed to detect shallow buried landmines by their vibrational characteristics. However, the influencing mechanisms of prodder’s components on the measured vibrational characteristics are not clear, and the vibration intensity of the buried landmine decreases with burial depth. A numerical analysis method is proposed to investigate the effects of parameters of prodder-object coupling system on the measured vibrational characteristics. The calculated main resonance frequency is 109.2 Hz, which corresponds well with the published analogy result of 110 Hz, and the mathematical method is also validated by the previous experimental results. Based on the proposed analysis method, an optimized prodder is designed, whereby the signal strength can theoretically increase 122.78%, which means that a greater depth of detection can be acquired. This optimal design is verified by the simulation experiment that was conducted with the optimization function of Adams software.


2013 ◽  
Vol 380-384 ◽  
pp. 1838-1842
Author(s):  
Zu Xu Zhou

Because of the frequent occurrence of injury accident in the sports curriculum, the security of physical education cannot be ignored. So, this paper analyzes the factors of injury accident in physical education teaching process and proposes prevention measures. The establishment of security system in physical education is an urgent problem. This paper studies the causes and countermeasures of sports injury accidents based on two methods: causality diagram and analytic hierarchy process. The first section introduces the principles of causality diagram and hierarchical analysis in detail. The second part of the article establishes mathematical model of the analysis method. The part three of the text investigates and analyzes the accident status and prevention measures of 100 primary schools and universities in Heilongjiang province in the form of literature researches and questionnaires. It also proposes weight coefficients and causality diagrams of Sports Injury Accidents using causal analysis theory. It converts causal diagram into a hierarchical model using the analytic hierarchy process AHP.


2013 ◽  
Vol 321-324 ◽  
pp. 2367-2370
Author(s):  
Xiao Nan Zhang ◽  
Si Lang Du ◽  
Jun Feng Yang ◽  
Wei Cao

It is found that the traditional BDA methods are not appropriate the system target BDA. A new method of the system target BDA is proposed in this paper. Firstly, based on Hierarchy Analysis Method (AHP), the system target function index system is set up. Secondly, the step of system target function damage assessment method is analyzed and proposed based on Fuzzy Analytic Hierarchy Process (FAHP). Finally, an example of air base damage assessment is given to verify the validity and availability of the proposed method.


2018 ◽  
Vol 22 (S1) ◽  
pp. 2255-2261 ◽  
Author(s):  
Xi Fei ◽  
Sun Youfu ◽  
Ruan Xuejun

Author(s):  
Takao Kondo ◽  
Kazuaki Kitou ◽  
Masao Chaki ◽  
Yukiharu Ohga ◽  
Takeshi Makigami

Japanese national project of next generation light water reactor (LWR) development started in 2008. Under this project, spectral shift rod (SSR) is being developed. SSR, which replaces conventional water rod (WR) of boiling water reactor (BWR) fuel bundle, was invented to enhance the BWR’s merit, spectral shift effect for uranium saving. In SSR, water boils by neutron and gamma-ray direct heating and water level is formed as a boundary of the upper steam region and the lower water region. This SSR water level can be controlled by core flow rate, which amplifies the change of average core void fraction, resulting in the amplified spectral shift effect. This paper presents the steady state test with varied SSR geometry parameters, the transient test, and the simulation analysis of these steady state and transient tests. The steady state test results showed that the basic functioning principle such as the controllability of SSR water level by flow rate was maintained in the possible range of geometry parameters. The transient test results showed that the change rate of SSR water level was slower than the initiating parameters. The simulation analysis of steady state and transient test showed that the analysis method can simulate the height of SSR water level and its change with a good agreement. As a result, it is shown that the SSR design concept and its analysis method are feasible in both steady state and transient conditions.


Open Physics ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 938-942 ◽  
Author(s):  
Xiaowei Yin ◽  
Wenxue Qian ◽  
Hoang Pham

AbstractEscalators are now more and more widely used around the world. As escalator accidents occur from time to time, it is very important to analyze the structure and reliability of escalators. This paper studies the structure and reliability analysis methods of typical escalators. By applying parametric analysis methods, the efficiency and accuracy of escalator structure analysis are greatly improved. Because the failure of each structural member of the escalator truss system is dependent, this paper applies the dependent failure reliability modeling method and analyzes the reliability of the escalator truss system. The results show that the reliability analysis method of the truss system after considering the dependent failure is more reasonable. The above research work has certain reference significance for the design and analysis of escalators.


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