THE INTEGRATION OF CAD/CAM/CAE BASED ON MULTI MODEL TECHNOLOGY IN THE DEVELOPMENT OF CYLINDER HEAD

Xu, Xiangyang,Weiss, Ulrich,Gao, Guoan The Korean Society of Automotive Engineers 2002 International journal of automotive technology Vol.3 No.2

The integration of CAD/CAM/CAE in product development is the key to realize concurrent engineering. Generally, different systems are employed in product development departments. These different systems create a lot of trout)toes such as difficulty in communication, misunderstanding and so on. A new approach to integrate CAD/CAM/CAE in one system based on CATIA thor the end-to-end process in cylinder head development is presented. Hulti Model Technology (MMT) is used to create consistent and associated CAD models for the end-to-end process in cylinder head development. The concept and method to create and organize multi models are discussed. A typical four-layer structure of HHT for mechanical products is defined. The multi level structure of the cylinder head models based on MMT is provided. The CAD models of cylinder head created based on MMT can be used as the consistent model. All models in the downstream of cylinder head development such as structure analysis, CFD, sand core design , casting simulation and so oil are associated with the CAD models. Practice shows the approach in this paper enables the development process to be carried concurrently and can obviously shorten time to the market, reduce product cost and improve product quality.

An investigation on the influence of modification parameters on transmission characteristics of planetary gear system

Xiangyang Xu,Xupeng Fan,Peng Diao,Huaiju Liu 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.7

A new gear tooth modification model of planetary gear system was established by considering the characteristics of tooth longitudinal crowning modification and tooth profile modification. Using this model, the influences of modification parameters on the time-varying mesh stiffness, transmission error, contact spots and dynamic response of the planetary gear system were analyzed through numerical analysis. The results show that tooth profile modification can effectively restrain the mesh stiffness sudden variation in the single and double tooth alternation of both the internal and external mesh pairs, and significantly decrease the transmission error fluctuation. However, longitudinal crowning modification has no marked influence on mesh stiffness sudden variation or transmission error fluctuation. The tooth profile modification can significantly reduce the sudden variation of tooth surface load during gear mesh course. Longitudinal crowning modification can make the tooth surface load evenly distributed in tooth width direction. When the external meshing pairs are modified at the tooth profile individually, the magnitude values of main response resonance peaks of internal meshing pairs have a great reduction, but those values of external meshing pairs change slightly. In the case of tooth profile modification of the internal meshing pairs, the phenomenon is reversed. By contrast with tooth profile modification, longitudinal crowning modification has little influence on the resonance peaks of internal and external meshing pairs.

Compressive strength estimation of eco-friendly geopolymer concrete: Application of hybrid machine learning techniques

Xiangyang Xu,Jiang Daibo,Hateo Gou 국제구조공학회 2022 Steel and Composite Structures, An International J Vol.45 No.6

Geopolymer concrete ( ) has emerged as a feasible choice for construction materials as a result of the environmental issues associated with the production of cement. The findings of this study contribute to the development of machine learning methods for estimating the properties of eco-friendly concrete to help reduce 2 emissions in the construction industry. The compressive strength ( ) of is predicted using artificial intelligence approaches in the present study when ground granulated blast-furnace slag ( ) is substituted with natural zeolite ( ), silica fume ( ), and varying concentrations. For this purpose, two machine learning methods multi-layer perceptron ( ) and radial basis function ( ) were considered and hybridized with arithmetic optimization algorithm ( ), and grey wolf optimization algorithm ( ). According to the results, all methods performed very well in predicting the of . The proposed − might be identified as the outperformed framework, although other methodologies ( − , − , and − ) were also reliable in the of forecasting process.

THE INTEGRATION OF CAD/CAM/CAE BASED ON MULTI MODEL TECHNOLOGY IN THE DEVELOPMENT OF CYLINDER HEAD

Xiangyang Xu,Ulrich Weiss,Guoan Gao 한국자동차공학회 2002 International journal of automotive technology Vol.3 No.2

The integration of CAD/CAM/CAE in product development is the key to realize concurrent engineering.<br/> Generally, different systems are employed in product development departments. These different systems create a lot of troubles such as difficulty in communication, misunderstanding and so on. A new approach to integrate CAD/CAM/CAE in one system based on CATIA for the end-to-end process in cylinder head development is presented. Multi Model Technology (MMT) is used to create consistent and associated CAD models for the end-to-end process in cylinder head development. The concept and method to create and organize multi models are discussed. A typical four-layer structure of MMT for mechanical products is defined. The multi level structure of the cylinder head models based on MMT is provided. The CAD models of cylinder head created based on MMT can be used as the consistent model. All models in the downstream of cylinder head development such as structure analysis, CFD, sand core design, casting simulation and so on are associated with the CAD models. Practice shows the approach in this paper enables the development process to be carried concurrently and can obviously shorten time to the market, reduce product cost and improve product quality.

The nonlinear effects of flexible pins on wind turbine gearboxes

Xiangyang Xu,Shaojiang Dong,Jiayuan Luo,Tianhong Luo 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.8

The structure of flexible pin-type planetary gear systems used in wind turbine gearboxes can improve the load sharing ability of planetswhile saving space unlike straddle-type carriers. However, the nonlinear dynamic characteristic of this type of system is not fully developed. This work presents a coupled lumped-parameter dynamic model to demonstrate nonlinear effects. Gear contact loss nonlinearityand bearing clearance nonlinearity are integrated into this dynamical model, and the effects of flexible pins on the nonlinear dynamicresponses are discussed. The conclusions made are as follows: lower flexible pin stiffness can significantly reduce nonlinear effects;when pin stiffness is increased, contact loss still occurs in positions of strong vibration even if the planet gear bearings have higher ordersof magnitude of tangential load in the wind turbine gearbox; dynamic response peaks are asymmetric with a frequency sweep; only leftoblique "Soft" jumps occur, and the right oblique “Hard” jump phenomena rarely occur; planet gear supporting the bearing clearanceexists; and vibration chaos occurs in positions of strong vibration.

Investigation on the heat transfer of MHD nanofluids in channel containing porous medium using lattice Boltzmann method

Xiangyang Liu,Jimin Xu,Tianwang Lai,Maogang He Techno-Press 2023 Advances in nano research Vol.15 No.3

In order to develop better method to enhance and control the flow and heat transfer inside the radiator of electronic device, the synergistic effect of MHD nanofluids and porous medium on the flow and heat transfer in rectangular opened channel is simulated using Lattice Boltzmann method. Three nanofluids of CuO-water, Al₂O₃-water and Fe₃O₄-water are studied to analyze the influence of the type of nanofluid on the synergistic effect. The simulation results show that the porous medium can increase the flow velocity in fluid zone adjacent to the porous medium and enhance the heat transfer on the surface of the channel. Under no magnetic field, when the porosity of porous medium is 0.8, the Nusselt number is 4.46% higher than when the porosity is 0.9. Al₂O₃-water has the best heat transfer effect among the three nanofluids. At Ф=0.06, Ha=100, θ=90°, ε=0.9, Nu of Al₂O₃-water is 6.51% larger than that of CuO-water and 5.05% larger than that of Fe₃O₄-water. Magnetic field enhances seepage in porous medium and inhibits heat transfer in the bottom wall. When Ha=30 and 60, the inhibiting effect is the most significant as the magnetic field angle is 90°. And when Ha=100, the inhibiting effect is the most significant as the magnetic field angle is 120°.

Verification Control Algorithm of Data Integrity Verification in Remote Data sharing

Guangwei Xu,Shan Li,Miaolin Lai,Yanglan Gan,Xiangyang Feng,Qiubo Huang,Lili Yang,Wei Li 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.2

Cloud storage's elastic expansibility not only provides flexible services for data owners to store their data remotely, but also reduces storage operation and management costs of their data sharing. The data outsourced remotely in the storage space of cloud service provider also brings data security concerns about data integrity. Data integrity verification has become an important technology for detecting the integrity of remote shared data. However, users without data access rights to verify the data integrity will cause unnecessary overhead to data owner and cloud service provider. Especially malicious users who constantly launch data integrity verification will greatly waste service resources. Since data owner is a consumer purchasing cloud services, he needs to bear both the cost of data storage and that of data verification. This paper proposes a verification control algorithm in data integrity verification for remotely outsourced data. It designs an attribute-based encryption verification control algorithm for multiple verifiers. Moreover, data owner and cloud service provider construct a common access structure together and generate a verification sentinel to verify the authority of verifiers according to the access structure. Finally, since cloud service provider cannot know the access structure and the sentry generation operation, it can only authenticate verifiers with satisfying access policy to verify the data integrity for the corresponding outsourced data. Theoretical analysis and experimental results show that the proposed algorithm achieves fine-grained access control to multiple verifiers for the data integrity verification.

Improvement of low-temperature NH3-SCR catalytic activity over Mn-Ce oxide catalysts supported on sewage sludge char activated with KOH and H3PO4

Junchao Xu,Xiangyang Zhang,Yunlan Sun,Hongming Long,Zhimin Zheng 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.12

Pyrolysis is a very potential sludge treatment technology that is low-cost and environmentally friendly; particularly, the pyrolysis sewage sludge char (SC) can be used as a catalyst support. To improve the NO conversion efficiency of sludge char based catalysts, they were activated by potassium hydroxide and phosphoric acid, respectively. The catalysts of activated sludge char with or without Mn-Ce impregnation in the application of NO removal by lowtemperature SCR were investigated. The higher NO conversion efficiency of sludge char based Mn-Ce catalysts at low temperature were obtained. Compared with the 59% NO conversion efficiency of Mn-Ce/SC catalyst, the conversion efficiency of catalyst supported on KOH activated char (SCK) achieved 89% at 220 oC and of catalyst supported on H3PO4 activated char (SCP) reached 87% at 240 oC. The catalysts were analytically characterized using N2 adsorptiondesorption, XRD, FTIR, NH3-TPD and XPS measurements. The higher specific area, excellent dispersion of Mn-CeOx and more Brønsted acid sites are responsible for the higher NO conversion efficiency of Mn-Ce/SCK, while the higher NO conversion efficiency of Mn-Ce/SCP is enhanced by more Brønsted acid sites, oxygen-containing and some unique phosphorus-containing oxygen functional groups. It indicates that sludge char activated by KOH and H3PO4 is a potential low-temperature catalyst support.

Verification Algorithm for the Duplicate Verification Data with Multiple Verifiers and Multiple Verification Challenges

( Guangwei Xu ),( Miaolin Lai ),( Xiangyang Feng ),( Qiubo Huang ),( Xin Luo ),( Li Li ),( Shan Li ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.2

The cloud storage provides flexible data storage services for data owners to remotely outsource their data, and reduces data storage operations and management costs for data owners. These outsourced data bring data security concerns to the data owner due to malicious deletion or corruption by the cloud service provider. Data integrity verification is an important way to check outsourced data integrity. However, the existing data verification schemes only consider the case that a verifier launches multiple data verification challenges, and neglect the verification overhead of multiple data verification challenges launched by multiple verifiers at a similar time. In this case, the duplicate data in multiple challenges are verified repeatedly so that verification resources are consumed in vain. We propose a duplicate data verification algorithm based on multiple verifiers and multiple challenges to reduce the verification overhead. The algorithm dynamically schedules the multiple verifiers’ challenges based on verification time and the frequent itemsets of duplicate verification data in challenge sets by applying FP-Growth algorithm, and computes the batch proofs of frequent itemsets. Then the challenges are split into two parts, i.e., duplicate data and unique data according to the results of data extraction. Finally, the proofs of duplicate data and unique data are computed and combined to generate a complete proof of every original challenge. Theoretical analysis and experiment evaluation show that the algorithm reduces the verification cost and ensures the correctness of the data integrity verification by flexible batch data verification.

Modular multilevel converter predictive control strategy based on energy balance

Xia, Xiangyang,Xu, Lei,Zhao, Xinxin,Zeng, Xiaoyong,Zhang, Jing,He, Yedan,Yi, Haigan The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.5

In MMC-HVDC (modular multilevel converter-based high-voltage direct current) applications, conventional control methods have defects such as complicated control and difficulty in controlling the internal energy of the converter. To ensure the safe and stable operation of an MMC-HVDC system, the problem of uneven internal energy distribution and increased fluctuations in the modular multilevel converter under asymmetrical network voltage conditions must be addressed. This paper has designed, a novel model predictive control (MPC) for MMC-HVDC applications. Through the proposed strategy, the switching states of all the MMC units can be optimized, which eliminates the circulating currents and achieves a voltage balance of the capacitor by redundant switching states. Moreover, an energy control circuit is established to adjust the DC bus power distribution in the MMC three-phase bridge arm. Thus, the symmetrical ac-side current can be realized, and the MMC internal energy imbalance caused by the transient process of the system can be avoided. Finally, the proposed novel predictive control strategy is tested via a case study. The obtained simulation and experimental results verify the effectiveness of the proposed control strategy.