Variation modeling for fuselage structures in large aircraft digital assembly

2015 ◽  
Vol 35 (2) ◽  
pp. 172-182 ◽  
Author(s):  
Liang Cheng ◽  
Qing Wang ◽  
Jiangxiong Li ◽  
Yinglin Ke
Keyword(s):  
Complex Structure ◽  
Dimensional Accuracy ◽  
Good Prediction ◽  
Assembly Process ◽  
Structure Model ◽  
Content Type ◽  
Aircraft Assembly ◽  
Beam Elements ◽  
Position Errors ◽  
Large Aircraft

Purpose – The aim of this paper is to present a new variation modeling method for fuselage structures in digital large aircraft assembly. The variation accumulated in a large aircraft assembly process will influence the dimensional accuracy and fatigue life of airframes. However, in digital large aircraft assembly, variation analysis and modeling are still unresolved issues. Design/methodology/approach – An elastic structure model based on beam elements is developed, which is an equivalent idealization of the actual complex structure. The stiffness matrix of the structure model is obtained by summing the stiffness matrices of the beam elements. For each typical stage of the aircraft digital assembly process, including positioning, coordinating, joining and releasing, variation models are built using the simplified structure model with respective loads and boundary conditions. Findings – Using position errors and manufacturing errors as inputs, the variations for every stage of the assembly process can be calculated using the proposed model. Practical implications – This method has been used in a large fuselage section assembly project, and the calculated results were shown to be a good prediction of variation in the actual assembly. Originality/value – Although certain assumptions have been imposed, the proposed method provides a better understanding of the assembly process and creates an analytical foundation for further work on variation control and tolerance optimization.

Propagation analysis of variation for fuselage structures in multi-station aircraft assembly

2018 ◽  
Vol 38 (1) ◽  
pp. 67-76 ◽  
Author(s):  
Liang Cheng ◽  
Qing Wang ◽  
Jiangxiong Li ◽  
Yinglin Ke
Keyword(s):  
Propagation Model ◽  
Analysis Approach ◽  
Good Prediction ◽  
Assembly Process ◽  
Content Type ◽  
Modeling And Analysis ◽  
Aircraft Assembly ◽  
Propagation Analysis ◽  
Variation Propagation ◽  
Large Aircraft

Purpose This paper aims to present a modeling and analysis approach for multi-station aircraft assembly to predict assembly variation. The variation accumulated in the assembly process will influence the dimensional accuracy and fatigue life of airframes. However, in digital large aircraft assembly, variation propagation analysis and modeling are still unresolved issues. Design/methodology/approach Based on an elastic structure model and variation model of multistage assembly in one station, the propagation of key characteristics, assembly reference and measurement errors are introduced. Moreover, the reposition and posture coordination are considered as major aspects. The reposition of assembly objects in a different assembly station is described using transformation and blocking of coefficient matrix in finite element equation. The posture coordination of the objects is described using homogeneous matrix multiplication. Then, the variation propagation model and analysis of large aircraft assembly are established using a discrete system diagram. Findings This modeling and analysis approach for multi-station aircraft assembly reveals the basic rule of variation propagation between adjacent assembly stations and can be used to predict assembly variation or potential dimension problems at a preliminary assembly phase. Practical implications The modeling and analysis approaches have been used in a transport aircraft project, and the calculated results were shown to be a good prediction of variation in the actual assembly. Originality/value Although certain simplifications and assumptions have been imposed, the proposed method provides a better understanding of the multi-station assembly process and creates an analytical foundation for further work on variation control and tolerance optimization.

Characterization of sintered hydroxyapatite samples produced by 3D printing

2014 ◽  
Vol 20 (5) ◽  
pp. 413-421 ◽  
Author(s):  
I. Pires ◽  
B. Gouveia ◽  
J. Rodrigues ◽  
R. Fonte
Keyword(s):  
Phase Stability ◽  
Mechanical Stability ◽  
Sintering Temperature ◽  
Calcium Phosphates ◽  
Complex Structure ◽  
Three Dimensional ◽  
Dimensional Accuracy ◽  
Compression Tests ◽  
Powder Morphology ◽  
Content Type

Purpose – The purpose of this study is to characterize sintered hydroxyapatite (HA) samples produced by three-dimensional printing (3DP). This study is part of a project concerned with the fabrication of calcium phosphates implants by 3DP. However, before considering a more complex structure, like scaffolds or implants, a thorough knowledge of the role played by the sintering temperature on physical and mechanical the properties of porous HA is necessary. Design/methodology/approach – The characteristics of sintered HA samples have been analyzed by means of x-ray diffraction, scanning electron microscope (SEM) and uniaxial compression tests. The 3DP parameters used to produce the HA samples were those who led to higher accuracy and mechanical stability. Findings – Sintering temperature and powder morphology are critical factors influencing densification behavior, porosity, phase stability, mechanical strength and tangent modulus of the HA samples produced by 3DP. This study allowed us to conclude about the 3DP parameters to be used to produce porous HA specimens with the required integrity and dimensional accuracy, and the optimal post-processing sintering temperature which led to the best results in terms of porosity, microstructure, phase stability of HA and mechanical properties. Originality/value – This paper provides a method to evaluate the manufacturability of calcium phosphate models produced by 3DP.

scholarly journals On Sequential-Pattern-Based Intelligent Compilation of Aircraft Assembly Process

2021 ◽  
Vol 1820 (1) ◽  
pp. 012106
Author(s):  
Sen-Shan Ouyang ◽  
Liang Song ◽  
Xiang-Feng Liu ◽  
Chen Chen ◽  
Zhen-Yu Chen
Keyword(s):  
Sequential Pattern ◽  
Assembly Process ◽  
Aircraft Assembly

An adaptive BPSO algorithm for multi-skilled workers assignment problem in aircraft assembly lines

2015 ◽  
Vol 35 (4) ◽  
pp. 317-328 ◽  
Author(s):  
Bo Xin ◽  
Yuan Li ◽  
Jianfeng Yu ◽  
Jie Zhang
Keyword(s):  
Cycle Time ◽  
Assignment Problem ◽  
Stability And Convergence ◽  
Binary Particle Swarm Optimization ◽  
Assembly Lines ◽  
Skilled Workers ◽  
Time Model ◽  
Content Type ◽  
Aircraft Assembly ◽  
Human Cost

Purpose – The purpose of this paper is to investigate the multi-skilled workers assignment problem in complex assembly systems such as aircraft assembly lines. An adaptive binary particle swarm optimization (A-BPSO) algorithm is proposed, which is used to balance the workload of both assembly stations and processes and to minimize the human cost. Design/methodology/approach – Firstly, a cycle time model considering the cooperation of multi-skilled workers is constructed. This model provides a quantitative description of the relationship between the cycle time and multi-skilled workers by means of revising the standard learning curve with the “Partition-And-Accumulate” method. Then, to improve the accuracy and stability of the current heuristic algorithms, an A-BPSO algorithm that suits for the discrete optimization problems is proposed to assign multi-skilled workers to assembly stations and processes based on modified sigmoid limiting function. Findings – The proposed method has been successfully applied to a practical case, and the result justifies its advantage as well as adaptability to both theory and engineering application. Originality/value – A novel cycle time model considering cooperation of multi-skilled workers is constructed so that the calculation results of cycle time are more accurate and closer to reality. An A-BPSO algorithm is proposed to improve the stability and convergence in dealing with the problems with higher dimensional search space. This research can be used by the project managers and dispatchers on assembly field.

Synthesis and properties of modified PBT for FDM

2017 ◽  
Vol 23 (4) ◽  
pp. 804-810 ◽  
Author(s):  
Shiqing Cao ◽  
Dandan Yu ◽  
Weilan Xue ◽  
Zuoxiang Zeng ◽  
Wanyu Zhu
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Fused Deposition Modeling ◽  
Complex Structure ◽  
Three Dimensional ◽  
Sebacic Acid ◽  
Wire Drawing ◽  
Content Type ◽  
Fused Deposition ◽  
Deposition Modeling

Purpose The purpose of this paper is to prepare a new modified polybutylene terephalate (MPBT) for fused deposition modeling (FDM) to increase the variety of materials compatible with printing. And the printing materials can be used to print components with a complex structure and functional mechanical parts. Design/methodology/approach The MPBT, poly(butylene terephalate-co-isophthalate-co-sebacate) (PBTIS), was prepared for FDM by direct esterification and subsequent polycondensation using terephthalic acid (PTA), isophthalic acid (PIA), sebacic acid (SA) and 1,4-butanediol (BDO). The effects of the content of PIA (20-40 mol%) on the mechanical properties of PBTIS were investigated when the mole per cent of SA (αSA) is zero. The effects of αSA (0-7mol%) on the thermal, rheological and mechanical properties of PBTIS were investigated at nPTA/nPIA = 7/3. A desktop wire drawing and extruding machine was used to fabricate the filaments, whose printability and anisotropy were tested by three-dimensional (3D) printing experiments. Findings A candidate content of PIA introducing into PBT was obtained to be about 30 per cent, and the Izod notched impact strength of PBTIS increased with the increase of αSA. The results showed that the PBTIS (nPTA/nPIA = 7/3, αSA = 3-5mol%) is suitable for FDM. Originality/value New printing materials with good Izod notched impact strength were obtained by introducing PIA and SA (nPTA/nPIA = 7/3, αSA = 3-5 mol%) into PBT and their anisotropy are better than that of ABS.

The prediction of the cyclic mechanical behavior of stainless steel 304L at room temperature

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hala Messai ◽  
Salim Meziani ◽  
Athmane Fouathia
Keyword(s):  
Stainless Steel ◽  
Design Methodology ◽  
Room Temperature ◽  
Type Model ◽  
Good Prediction ◽  
304L Stainless Steel ◽  
Content Type ◽  
The Third ◽  
Chaboche Model

Purpose The purpose of this paper is to highlight the performance of the Chaboche model in relation to the database identification, tests with imposed deformations were conducted at room temperature on 304L stainless steel specimens. Design/methodology/approach The first two tests were performed in tension-compression between ±0.005 and ±0.01; in the third test, each cycle is composed of the combination of a compression tensile cycle between ±0.01 followed by a torsion cycle between ±0.01723 (non-proportional path), and the last, uniaxial ratcheting test with a mean stress between 250 MPa and −150 MPa. Several identifications of a Chaboche-type model were then performed by considering databases composed of one or more of the cited tests. On the basis of these identifications, the simulations of a large number of ratchet tests in particular were carried out. Findings The results present the effect of the optimized parameters on the prediction of the behavior of materials which is reported in the graphs, Optimizations 1 and 2 of first and second tests and Optimization 4 of the third test giving a good prediction of the increasing/decreasing pre-deformation amplitude. Originality/value The quality of the model's predictions strongly depends on the richness of the database used for the identification of the parameters.

Investigation of dimensional accuracy of metal droplet deposition under repulsion using a lattice Boltzmann approach

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yanlin Ren ◽  
Zhaomiao Liu ◽  
Yan Pang ◽  
Xiang Wang ◽  
Shanshan Gao
Keyword(s):  
Lattice Boltzmann ◽  
Moving Boundary ◽  
Three Dimensional ◽  
Metal Droplet ◽  
Dimensional Accuracy ◽  
Longitudinal Section ◽  
Collision Term ◽  
Droplet Deposition ◽  
Content Type ◽  
Deposition Distance

Purpose This paper aims to investigate the influence of droplet infiltration and sliding on the deposition size and make a uniform deposition by controlling the interaction between droplets, using the three-dimensional lattice Boltzmann method (LBM) based on the actual working condition. Design/methodology/approach D3Q19 Shan-Chen LB approach is developed and optimized based on the metal droplet deposition. The Carnahan-Starling equation of state and transition layers are introduced to maintain the greater stability and low pseudo velocities. In addition, an additional collision term is adopted to implement immersed moving boundary scheme to deal with no-slip boundaries on the front of the phase change. Findings The numerical results show that the new¬ incoming droplet wet and slide off the solidified surface and the rejection between droplets are the reasons for the deviation of the actual deposition length. The total length of the longitudinal section negatively correlates with the deposition distance. To improve the dimensional accuracy, the deposition distance and repulsion rate need to be guaranteed. The optimal deposition distance is found to have a negative linear correlation with wettability. Originality/value The numerical model developed in this paper will help predict the continuous metal droplet deposition and provide guidance for the selection of deposition distance.

Complex Fastener Model for Simulation of Airframe Assembly Process

2020 ◽  
Author(s):  
Sergey Lupuleac ◽  
Aleksandr Smirnov ◽  
Julia Shinder ◽  
Margarita Petukhova ◽  
Maria Churilova ◽  
...  
Keyword(s):  
Contact Interaction ◽  
Stiffness Matrix ◽  
Complex Model ◽  
Assembly Process ◽  
Optimization Analysis ◽  
Global Modeling ◽  
Aircraft Assembly ◽  
Simulation Results ◽  
Variation Simulation ◽  
Model Dimension

Abstract The complex model of fastener for the global modeling of aircraft assembly with regard to compliance and contact interaction of parts is introduced in the paper. The presented complex fastener model incorporates such effects as the stiffness of fastening elements; the loosening of fasteners and also the failure of fasteners (if the load exceeds the maximal value that fastener can hold). This model can be implemented for all types of fastening elements in variation simulation and assembly optimization analysis. It provides more realistic simulation results at expense of higher model dimension. The fastener is modeled as having an additional stretching stiffness. The option of fastener loosening is included by implementation of additional contact node in each fastening element. This option allows taking into account the pre-tension in fasteners and also enables the modeling of installation and removal of fasteners without change of stiffness matrix.

A self-developed indoor three-dimensional pedestrian localization platform based on MEMS sensors

Sensor Review ◽  
2015 ◽  
Vol 35 (2) ◽  
pp. 157-167 ◽  
Author(s):  
Shengbo Sang ◽  
Ruiyong Zhai ◽  
Wendong Zhang ◽  
Qirui Sun ◽  
Zhaoying Zhou
Keyword(s):  
Low Cost ◽  
Angular Rate ◽  
Three Dimensional ◽  
Dead Reckoning ◽  
Rate Data ◽  
Mems Sensors ◽  
Micro Electro Mechanical Systems ◽  
Content Type ◽  
Position Errors ◽  
Low Performance

Purpose – This study aims to design a new low-cost localization platform for estimating the location and orientation of a pedestrian in a building. The micro-electro-mechanical systems (MEMS) sensor error compensation and the algorithm were improved to realize the localization and altitude accuracy. Design/methodology/approach – The platform hardware was designed with common low-performance and inexpensive MEMS sensors, and with a barometric altimeter employed to augment altitude measurement. The inertial navigation system (INS) – extended Kalman filter (EKF) – zero-velocity updating (ZUPT) (INS-EKF-ZUPT [IEZ])-extended methods and pedestrian dead reckoning (PDR) (IEZ + PDR) algorithm were modified and improved with altitude determined by acceleration integration height and pressure altitude. The “AND” logic with acceleration and angular rate data were presented to update the stance phases. Findings – The new platform was tested in real three-dimensional (3D) in-building scenarios, achieved with position errors below 0.5 m for 50-m-long route in corridor and below 0.1 m on stairs. The algorithm is robust enough for both the walking motion and the fast dynamic motion. Originality/value – The paper presents a new self-developed, integrated platform. The IEZ-extended methods, the modified PDR (IEZ + PDR) algorithm and “AND” logic with acceleration and angular rate data can improve the high localization and altitude accuracy. It is a great support for the increasing 3D location demand in indoor cases for universal application with ordinary sensors.

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