DESIGN AND OPTIMIZATION OF INNOVATIVE FIXTURE AND GAUGE FOR A LANDING GEAR STATOR

International Journal of Mechanical and Production Engineering Research and Development (IJMPERD) ISSN (P): 2249–6890; ISSN (E): 2249–8001 Vol. 10, Issue 3, Jun 2020, 3881-3886 © TJPRC Pvt. Ltd.

DESIGN AND OPTIMIZATION OF INNOVATIVE FIXTURE AND GAUGE FOR A LANDING GEAR STATOR ARUNA KUMARA P C1, D.VENKATESH2 & SHIVA KRISHNA J3 1,2

Assistant Professor, M S Ramaiah Institute of Technology, Bangalore, Karnataka, India 3

Assistant Professor, Agnel Institute of Technology and Design, Assagao, Goa, India

ABSTRACT Manufacturing and inspecting the parts to high precision is very challenging and time consuming task. The current sets of gauges for inspection of landing gear stator are more time consuming and labor oriented, adding lot of cost and delay in the inspection time. This paper shows optimization the inspection process by reducing inspection time and labor cost using an innovative gauge and fixture by conceptualizing, designing, engineering, manufacturing and validation of a single gauge which take care of the inspection cycle.

Conceptual models of the gauge and fixture is to be generated by studying the product drawings, GD&T requirements, reliability requirements and other critical areas. The best concept is selected using Pugh matrix method.

The model is to be then analyzed through ANSYS workbench.

Conceptual models of the gauge and fixture is to be generated by studying the product drawings, GD&T requirements, reliability requirements and other critical areas. The best concept is selected using Pugh matrix method.

Preliminary design of the gauge with functional features and mechanisms is to be carried out using CATIA software.

The model is to be then analyzed through ANSYS workbench.

Original Article

Preliminary design of the gauge with functional features and mechanisms is to be carried out using CATIA software.

KEYWORDS: Product design, Fixture, Gauge, Pugh Matrix & DFMA

Received: Jun 10, 2020; Accepted: Jun 30, 2020; Published: Jul 17, 2020; Paper Id.: IJMPERDJUN2020370

INTRODUCTION Landing gear is the undercarriage of an aircraft which supports the craft when it is not flying. The main functions of the landing gear include energy absorption at landing, braking and taxi control. Landing gear steering actuator has a coaxial stator and rotor ring assembly mounted on the fixed outer cylinder of a nose landing gear shock absorber strut that helps in steering the braking the craft.

The fixture designing and manufacturing is considered as complex process that demands the knowledge of different areas, such as geometry, tolerances, dimensions, procedures and manufacturing processes. While designing this work, a good number of literature and titles written on the subject by renowned authors are referred.

All findings and conclusions obtained from the literature review and the interaction with fixture designers are used as guide to design the present research work.

As stated by Koji Teramoto et al. [1], Fixturing Plan (FP) and Machining Plan (MP) are mutually dependent. Implicit to this conclusion, paper coordinates MP and FP by coupling a fixture designing with manufacturing, mass balancing and finite element analysis. For this research, a relevant issue when considering requirements, taking this as a general concept, is to make explicit the meaning of two main terms: Functional www.tjprc.org

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Requirement (FR) and Constraint (C) [2]. Functional Requirement (FR), as it stated by different authors, “represents what the product has to or must do independently of any possible solution.” Constraint (C) can be defined as “a restriction that in general affects some kind of requirement, and it limits the range of possible solutions while satisfying the requirements[3].

METHODOLOGY

Figure 1: General Procedure A careful study on product drawings, existing fixture/gauge, inspection techniques, reliability requirements and other critical areas is done. Brainstorming is made concepts are generated. Concepts are rated and the best concept is selected using Pugh selection matrix. A preliminary CAD models with all the functional features are then created using CATIA software. The models are analyzed using ANSYS workbench and are updated as per the CAE findings. The 2D drawings of the parts are created along with assembly drawings BOM is generated. CNC programming is made for manufacturing all the parts. After manufacturing a third party inspection is made to ensure the parts manufactured are as per the specifications [4, 5]. The gauge is assembled per the specifications, the job is inspected and the test reports are created[6].

COMPONENT DETAILS

Figure 2: Stator Laminator Impact Factor (JCC): 8.8746

Figure 3: Stator Assembly

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Design and Optimization of Innovative Fixture and Gauge for a Landing Gear Stator

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The component is stator laminator [Fig 2] of an aircraft landing gear, made up of aluminum, 5mm thick generally produced by punching operation. The component is used to generate the power on the reaction of rotor and is used to charge the batteries in the aircraft. It has an internal diameter of 167.12 mm and an external diameter of 232.3mm. The laminator plates are assembled by an adhesive to a thickness of 73.5mm [Fig 3]. It has 12 holes on PCD of 220mm, 3 holes of 5.05mm diameter spread uniformly around the PCD and 9 holes of 4.44mm spread uniformly in-between them.

Concept Generation and Assessment A careful study on product drawings, existing fixture/gauge, inspection techniques, reliability requirements and other critical areas is made[7]. Three design concepts were generated. The evaluation of design concepts is done by Pugh matrix method. The Pugh Matrix is a type of Matrix Diagram that allows the comparison of a number of design concepts leading to the selection of best one by evaluating the design concepts according to their strengths and weaknesses against a reference concept called the datum.

Figure 4: Design Concept 1

Figure 5: Design Concept 2

The Design Concept 1 [Fig 4] consists of a simple shaft like structure attached to the base plate. The stator assembly is located around it as the outer diameter of the shaft structure is equal to that of inner of the job. The circular projection is made on the top plate to match the axis of top plate and the job and the holes are located by inserting pins into the holes present on the top plate.

In Design Concept 2, as illustrated in [Fig 6] has a small projection on the bottom plate with a rubber lining around which the stator assembly is located. A press fit is created which locks the motion of the job. The pins are attached to the top plate which is supported by a spring[8].

The Design Concept 3 [Fig 7] consists of a collapsible core which arrests the job on rotating the vertical mandrel.

This concept arrests all the degrees of freedom of the job when compared to the other two concepts. The holes are located by inserting the pins into the top plate.

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Figure 6: Design Concept 3

Criteria Functionality Manufacturability Weight Safety Reliability Serviceability Portability User Interface Aesthetics Total Rank

Table 1: Pugh matrix Baseline Concept 1 Concept 2 2 1 3 3 4 3 3 4 3 3 4 3 3 3 3 2 3 2 2 4 3 3 3 3 3 3 3 29 26 2 3

Concept 3 4 4 3 4 4 4 4 4 3 34 1

From the Pugh matrix in Table 1, it can be seen that Design Concept 3 was the most preferable choice, while Design Concept 2 was the least desirable. Design Concept 2 was assessed to have a longer service time and less safe when compared to others. However, Design Concept 1 violated the due to functionality, as it doesn’t arrest the motion of the job completely. It can be seen that Design Concept 3 was better than in all respect when compared to others.

ANALYSIS Deflection and Stress distribution in the top plate and base plate is analyzed using Ansys workbench. This analysis is necessary in order to decide their appropriate thickness.

Figure 7: Deflection in Top Plate

Impact Factor (JCC): 8.8746

Figure 8: Stress Distribution in Top Plate

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Design and Optimization of Innovative Fixture and Gauge for a Landing Gear Stator

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Table 2: Deflection and Stress distribution Values for Top Plate Plate Thickness (mm) 5 6 7 8 9 10

Deflection (m) 1.4656e-5 9.9166e-6 7.0993e-6 5.0414e-6 3.8808e-6 3.3153e-6

Stress (N/m²) 5.5029e6 4.3733e6 3.6443e6 2.9254e6 2.5158e6 2.3777e6

Table 3: Deflection and Stress Distribution values for Top plate Plate Thickness (mm) Deflection (m) Stress (N/m²) 8 5.3357e-6 6.8859e5 10 2.7118e-6 4.6252e5 12 1.5711e-6 3.2759e5 14 9.9583e-7 2.5464e5

Figure 9: Deflection in Base Plate

Figure 10: Stress Distribution in Base plate

The deflection and stress values can be further reduced by increasing the thickness of the plate, which in turn increases the weight of the component. The thickness of 8mm for the Top plate and 12mm for the bottom plate is sufficient to serve the purpose.

CONCLUSIONS A simple mechanical design of gauge and fixture is developed for inspecting the landing gear stator assembly. The best concept was chosen by comparing the strengths and weaknesses using Pugh matrix. The appropriate thickness of the Top plate and Base plate are using selected by static structural analysis using ANSYS workbench.

REFERENCES 1.

Koji Teramoto, Masahiko Anasoto and Kazuaki Iwata, “Coordinative Generation of Machining and Fixturing Plans by a Modularized Problem Solver,” CIRP Annals-Manufacturing Technology 1998, 47(1), pp. 437-440.

2.

Hunter R., Rios J., Perez J. M., and Vizan A., “A functional approach for the formalization of the fixture design process,” International Journal of Machine Tools and Manufacture 2006, 46(6), pp. 683-697.

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Aruna Kumara P C, D. Venkatesh & Shiva Krishna J Jigar D Suthar1, K.M .Patel1, and Sanjay G Luhana, “Design and analysis of fixture for welding an exhaust impeller”, Chemical, Civil and Mechanical Engineering Tracks of 3rd Nirma University International Conference 2013.

4.

S.H. Yeo, M.W. Mak and A.P. Balon, “Analysis of Decision-making Methodologies for Desirability Score of Conceptual Design”, Journal of Engineering Design, Vol. 15, 2004, pp. 195-208.

5.

A.M. King and S. Sivaloganathan, “Development of a Methodology for Concept Selection in Flexible Design Strategies”, Journal of Engineering Design, Vol. 10, 1999, pp. 329-349.

6.

K.T. Ulrich, and S.D. Eppinger, Product Design and Development 2nd ed., McGraw-Hill, New York, 2000.

7.

Daniel D Frey, E Paulien M. Herder, “The Pugh Controlled Convergence method: model-based evaluation and implications for design theory”, Res Eng Design 2009.

8.

Nirav P. Maniar, D. P. Vakharia, Chetan M. Patel, “Design & Manufacturing With Modeling, Dynamic Balancing & Finite Element Analysis of Rotary Fixture for CNC Turning Centre to Function as Hmc”, ASME ECTC October 2-3, 2009

Impact Factor (JCC): 8.8746

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NAAS Rating: 3.11