Assembly variation analysis of the aircraft panel in multi-stage assembly process with N-2-1 locating scheme

2019 ◽  
Vol 233 (19-20) ◽  
pp. 6754-6773 ◽  
Author(s):  
Cong Lu ◽  
Deng-Sheng Huo ◽  
Zi-Yue Wang
Keyword(s):  
Contact Force ◽  
Assembly Process ◽  
Variation Analysis ◽  
Assembly Quality ◽  
Aircraft Fuselage ◽  
Multi Stage ◽  
Assembly Accuracy ◽  
Flexible Panel

The flexible aircraft panel parts are easy to deform during the assembly process, the deformation can directly affect the assembly accuracy of the aircraft panel, and further affect the assembly quality of the aircraft fuselage. In order to evaluate the assembly accuracy of the aircraft panel in multi-stage assembly process with N-2-1 locating scheme, this paper proposes an assembly variation analyzing approach, considering the effect of the contact force between the panel skin and the fixture components on the deformation of the panel in the assembly process. The mathematical models are established to conclude the contact force between the panel skin and the fixture components in multi-stage assembly process of the panel with N-2-1 locating scheme, and the effect of the contact force between the skin and the fixture components on the deformation of the panel in assembly is investigated. An assembly variation model is built for the aircraft panel considering the variation sources including the manufacturing error of the flexible panel parts, fixture error, and the deformation of the panel in multi-stage assembly process considering the effect of the contact force. Finally, the proposed assembly variation analyzing approach for the aircraft panel is tested with a case study.

A Design Procedure for Multistage External Gear Pumps

2020 ◽  
Author(s):  
Davide Guerra ◽  
Marco Polastri ◽  
Mattia Battarra ◽  
Alessio Suman ◽  
Emiliano Mucchi ◽  
...  
Keyword(s):  
Design Procedure ◽  
Target Delivery ◽  
Multi Stage ◽  
External Gear Pumps ◽  
Geometrical Features ◽  
Fluid Properties ◽  
Gear Pumps ◽  
Working Parameters

Abstract In this work, the authors present a robust and integrated procedure for the design of multi-stage gear pumps to be used in dry sump system applications. Based on the target delivery flow rate, rotational speed and fluid properties, the developed iterative method enables to directly obtain the geometrical features and the working parameters of the pump components, such as gearpair specifics, shaft and journal bearing dimensions, clearance values. The methodology is then applied to a case study in order to highlight its features and detail the achievable outcomes. Quality of the results is assessed by means of a CFD analysis, demonstrating the capability to obtain the expected volumetric efficiency.

scholarly journals Assembly Variation Analysis of Aircraft Panels under Part-to-part Locating Scheme

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Xia Liu ◽  
Luling An ◽  
Zhiguo Wang ◽  
Changbai Tan ◽  
Xiaoping Wang ◽  
...  
Keyword(s):  
Elastic Deformation ◽  
Assembly Process ◽  
Variation Analysis ◽  
Kinematic Theory ◽  
Statistical Variation ◽  
Variation Propagation ◽  
Fixed Part ◽  
Compliant Parts ◽  
Aircraft Panels

A typical aircraft panel is the assembly consisting of a multitude of thin and lightweight compliant parts. In panel assembly process, part-to-part locating scheme has been widely adopted in order to reduce fixtures. By this locating scheme, a part is located onto the pre-fixed part/subassembly by determinant assembly (DA) holes, and temporary fasteners (e.g., spring pin) are used for joining these DA hole-hole pairs. The temporary fasteners can fasten DA hole-hole pairs in the axial and radial directions of DA holes. The fastening in the radial directions is realized by the expansion of temporary fasteners. Although the usage of temporary fasteners helps reduce the positional differences between hole-hole pairs, their clamping forces thereby may lead to elastic deformation of compliant parts/subassemblies. Limited research has been conducted on such elastic deformation produced by temporary fastener and its influence on assembly dimensional quality. This paper proposes a novel rigid-compliant variation analysis method for aircraft panel assembly, incorporating the deformation in part-to-part locating process. Based on the kinematic theory and linear elasticity deformation assumption, the variation propagation through the locating process, as well as the entire assembly process of an aircraft panel, is formulated. Then, the statistical variation analysis is performed with Monte Carlo (MC) simulation. Finally, the proposed method is validated by a case study. The result shows the deformation in the part-to-part locating process significantly impacts the assembly variations, and our method can provide a more accurate and reliable prediction.

Familial clustering of Amelogenesis Imperfecta – a case study

2018 ◽  
Vol 14 (1) ◽  
pp. 61-72
Author(s):  
Agnieszka Kornet ◽  
Michał Kornet ◽  
Roksana Domańska ◽  
Konrad Perkowski ◽  
Magdalena Marczyńska-Stolarek ◽  
...  
Keyword(s):  
Open Bite ◽  
Amelogenesis Imperfecta ◽  
Multi Stage ◽  
Familial Clustering ◽  
Proper Functions ◽  
Medical University ◽  
Tooth Buds

Amelogenesis Imperfecta (henceforth: AI) is a term used to determine congenital qualitative and quantitative enamel defects, concerning both deciduous and permanent dentition. Classification of AI is based on the phenotype of lesions and is included in numerous types of classifications, among which the Witkop classification is the most popular. Apart from enamel abnormalities, patients afflicted with AI may also have other disorders, e.g. congenital deficiencies of tooth buds, pulp calcification, root and crown resorption, open bite. Aesthetic defects of dentition, pain reported when consuming acidic and hot foods, difficulties in obtaining satisfactory hygiene - all these significantly affect the quality of life of patients with AI. Care provided to these patients is highly specialised and starts as early as in early childhood. Aim. The aim of the study was to describe familial clustering, types, symptoms and treatment of Amelogenesis Imperfecta in members of two families treated at the Department of Orthodontics at the Medical University of Warsaw. Material and methods. The material comprised two unrelated families with clinically manifested symptoms of AI, treated at the Department of Orthodontics at the Medical University of Warsaw. A detailed interview, clinical examination and analysis of radiological documentation were conducted in each family. Results. All patients in the study were suffering from hypoplastic AI, their hygiene was satisfactory, four in five patients had an open bite. Reported symptoms did not differ from those most commonly described in the literature, and included discomfort while eating acidic and hot food, and excessive enamel abrasion. Conclusions. Treatment of patients with AI is multi-stage, multidisciplinary, and aims to restore proper functions of the dentition, as well as to obtain a correct occlusion, skeletal relationships, and to reduce hypersensitivity to thermal and chemical stimuli. Preventive measures are important, and should be introduced early, during the stage of the deciduous dentition, and be related to hygiene briefing and monitoring. (Kornet A, Kornet M, Domańska R, Perkowski K, Marczyńska-Stolarek M, Zadurska M. Familial clustering of Amelogenesis Imperfecta – a case study. Orthod Forum 2018; 14: 61-72)

Measuring the assembly quality from the operator mistake view: a case study

2009 ◽  
Vol 29 (4) ◽  
pp. 332-340 ◽  
Author(s):  
Qiang Su ◽  
Lei Liu ◽  
Shengjie Lai
Keyword(s):  
Prediction Model ◽  
Assembly Quality ◽  
Content Type ◽  
Standard Time ◽  
Rate Prediction ◽  
Defect Rate ◽  
Proposed Model ◽  
Assembly Defect

PurposeThe purpose of this paper is to focus on the assembly quality of copier products, specifically, concentrating on the prediction of the operator‐induced assembly defect.Design/methodology/approachBased on the Shibata model, the design‐based assembly complexity is redesigned. And the Sony Standard Time is replaced by the Fuji Xerox Standard Time in the calculation of the process‐based assembly complexity. Furthermore, different correlation functions are attempted and comparatively studied in the regression analysis. Thereby, a new defect rate prediction model is proposed and validated with three copier assembly cases.FindingsThe new proposed model is much more accurate and stable in the human‐induced assembly defect prediction in copier production.Practical implicationsThe proposed model can be used to ensure the assembly quality by removing potential defects at the structure and process design stages. Meanwhile, with this model, the interactions between the engineers and designers can be more effective.Originality/valueThis paper presents a novel assembly defect rate prediction model for copier assembly quality management.

Design of Automatic Assembly System of Saw Chain

2011 ◽  
Vol 141 ◽  
pp. 239-243
Author(s):  
Ze Xin Ding ◽  
Feng Yuan ◽  
Jun Zhu
Keyword(s):  
Poor Quality ◽  
Assembly System ◽  
Positioning System ◽  
Assembly Process ◽  
Automatic Assembly ◽  
Assembly Quality ◽  
Assembly Method ◽  
Low Efficiency

The automatic assembly system of saw chain is designed to solve the low efficiency and poor quality of its assembly process according to the actual requirements of production. Firstly, the structure of saw chain and its automatic assembly requirements are analysed. Secondly, the different design plans on assembly process and assembly method are proposed and compared. Finally, the automatic assembly system of saw chain is designed, which is composed of feeding device and clamp positioning system. This system can not only realize the automatic assembly of saw chain, but also improve the assembly quality and prolong the using life of saw chain.

A Method for Identifying Error Sources in Complex Assembly Process Based on Multi-Level Network

2014 ◽  
Author(s):  
Guangzhou Diao ◽  
Liping Zhao ◽  
Yiyong Yao ◽  
Sheng Hu
Keyword(s):  
Product Quality ◽  
Error Compensation ◽  
Product Performance ◽  
Self Organization ◽  
Assembly Process ◽  
Assembly Quality ◽  
Error Sources ◽  
Complex Assembly ◽  
Multi Level

In complex assembly process, there are many error sources which influence the final product quality, so the identification and compensation of error sources are the important ways to improve product quality. The purpose of this paper is to identify the error sources by establishing the relationships between assembly errors and product performance. Firstly, a new concept of multi-level network is proposed to describe the complexity of product structure. Then the multi-level assembly network (MLAN) model is established and its self-organization stability is discussed to explore the influences from assembly errors on product performance. The sensitive fluctuation index (SFI) is defined and calculated to identify the error sources in assembly process. Based on this, the error sensitivity is discussed so that measures for error compensation are made to improve the assembly quality of product. Finally, an assembly experiment about blade rotation is conducted to verify the feasibility of proposed method.

Assembly Process Application of Lean Quality Management

2011 ◽  
Vol 347-353 ◽  
pp. 225-227
Author(s):  
Mo Li Sun ◽  
Xiao Chun Zhang
Keyword(s):  
Quality Control ◽  
Quality Management ◽  
Business Performance ◽  
Process Analysis ◽  
Enterprise Performance ◽  
Assembly Process ◽  
Assembly Quality ◽  
Product Assembly ◽  
Analysis Quality

The product assembly as the final manufacturing process is one of the most important part, its quality has a major impact on product quality. Application of lean quality management in product assembly improve the assembly quality, efficiency and cost are the quality management of the new trends. Research on quality management, analysis all aspects of quality control around the assembly process, store electronic resume of assembly process, analysis quality defect, forecast and optimize the matching of key parts, which significantly improve the quality of the assembly process of the enterprise performance and business performance.

scholarly journals Comparing Augmented Reality-Assisted Assembly Functions—A Case Study on Dougong Structure

2020 ◽  
Vol 10 (10) ◽  
pp. 3383 ◽  
Author(s):  
Chih-Hsing Chu ◽  
Chien-Jung Liao ◽  
Shu-Chiang Lin
Keyword(s):  
Augmented Reality ◽  
Assembly Process ◽  
Functional Design ◽  
Complex Objects ◽  
Manual Assembly ◽  
Scale Models ◽  
Architectural Innovation ◽  
Assembly Instructions

The Dougong structure is an ancient architectural innovation of the East. Its construction method is complex and challenging to understand from drawings. Scale models were developed to preserve this culturally-unique architectural technique by learning through their assembly process. In this work, augmented reality (AR)-based systems that support the manual assembly of the Dougong models with instant interactions were developed. The first objective was to design new AR-assisted functions that overcome existing limitations of paper-based assembly instructions. The second one was to clarify whether or not and how AR can improve the operational efficiency or quality of the manual assembly process through experiments. The experimental data were analyzed with both qualitative and quantitative measures to evaluate the assembly efficiency, accuracy, and workload of these functions. The results revealed essential requirements for improving the functional design of the systems. They also showed the potential of AR as an effective human interfacing technology for assisting the manual assembly of complex objects.

Misophonia: An Evidence-Based Case Report

2020 ◽  
Vol 29 (4) ◽  
pp. 685-690
Author(s):  
C. S. Vanaja ◽  
Miriam Soni Abigail
Keyword(s):  
Quality Of Life ◽  
Case Report ◽  
Case History ◽  
Pure Tone ◽  
Physiological Responses ◽  
Evidence Based ◽  
Management Option ◽  
Pure Tone Audiogram

Purpose Misophonia is a sound tolerance disorder condition in certain sounds that trigger intense emotional or physiological responses. While some persons may experience misophonia, a few patients suffer from misophonia. However, there is a dearth of literature on audiological assessment and management of persons with misophonia. The purpose of this report is to discuss the assessment of misophonia and highlight the management option that helped a patient with misophonia. Method A case study of a 26-year-old woman with the complaint of decreased tolerance to specific sounds affecting quality of life is reported. Audiological assessment differentiated misophonia from hyperacusis. Management included retraining counseling as well as desensitization and habituation therapy based on the principles described by P. J. Jastreboff and Jastreboff (2014). A misophonia questionnaire was administered at regular intervals to monitor the effectiveness of therapy. Results A detailed case history and audiological evaluations including pure-tone audiogram and Johnson Hyperacusis Index revealed the presence of misophonia. The patient benefitted from intervention, and the scores of the misophonia questionnaire indicated a decrease in the severity of the problem. Conclusions It is important to differentially diagnose misophonia and hyperacusis in persons with sound tolerance disorders. Retraining counseling as well as desensitization and habituation therapy can help patients who suffer from misophonia.

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