1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2012 SAE International All rights reserved. No part of this publication m
3、ay be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970 (outside U
4、SA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/ARP4146C AEROSPACE RECOMMENDED PRACTICE ARP4146 REV. C Issued 1990-03 Reaffirmed 1994-05 Revi
5、sed 2012-12 Superseding ARP4146B Coiled Tubing Titanium Alloy, Hydraulic Applications, Aerospace RATIONALE ARP4146C corrects an equation in 7.1.2. TABLE OF CONTENTS 1. SCOPE 3 1.1 Purpose . 3 1.2 Field of Application 3 2. APPLICABLE DOCUMENTS 3 2.1 SAE Publications . 3 2.2 U.S. Government Publicatio
6、ns 4 3. CONFIGURATIONS . 4 3.1 Style A - Helical Torsion Configuration . 4 3.2 Style B - Torsion Tube Configuration 6 3.3 Style C - Helical Compression/Extension Configuration . 7 3.4 Style D - Tri-Coil Compression/Extension Configuration 8 3.5 Style E - Oval Compression/Extension Configuration 9 4.
7、 MATERIAL PROPERTIES 10 4.1 Basic Allowables . 10 4.2 Endurance Allowables 10 4.3 Contractile Strain Ratio . 10 5. STRESS ANALYSIS . 11 6. FITTINGS 11 7. FABRICATION 11 7.1 Style A . 11 7.1.1 Conventional Tooling 11 7.1.2 Spiral Mandrel . 11 7.1.3 Other Tooling 13 7.2 Style B . 13 7.3 Style C . 13 7
8、.4 Style D . 13 7.5 Style E . 13 7.6 Surface Finish . 13 7.7 Autofrettage . 13 SAE ARP4146C Page 2 of 43 8. INSTALLATION . 14 8.1 Style A Installation . 14 8.2 Style B Installation . 16 8.3 Style C Installation 16 8.4 Style D Installation 16 8.5 Style E Installation . 16 9. VIBRATION DAMPING . 16 9.
9、1 CRES Wire Rope 17 9.2 Ties and Loops 17 9.3 Commercial Wire Rope Damper . 18 10. NOTES 18 APPENDIX A DESIGN DATA FOR STYLE A CONFIGURATION 19 FIGURE 1 STYLE A - HELICAL TORSION CONFIGURATION 5 FIGURE 2 STYLE B - TORSION TUBE CONFIGURATION 6 FIGURE 3 STYLE C - HELICAL COMPRESSION/EXTENSION CONFIGUR
10、ATION . 7 FIGURE 4 STYLE D - TRI-COIL COMPRESSION/EXTENSION CONFIGURATION . 8 FIGURE 5 STYLE E - OVAL HELICAL COMPRESSION/EXTENSION CONFIGURATION . 9 FIGURE 6 SPIRAL MANDREL COILING TOOL 12 FIGURE 7 CENTERLINE LIMITS FOR STYLE A COILED TUBE INSTALLATION 15 FIGURE 8 CRES WIRE ROPE DAMPER 17 FIGURE 9
11、COMMERCIAL WIRE ROPE DAMPER . 18 SAE ARP4146C Page 3 of 43 1. SCOPE This SAE Aerospace Recommended Practice (ARP) addresses the design, installation, and testing of coiled tube assemblies using Ti-3Al-2.5V cold worked, stress relieved (CWSR) tubing per AMS4945. It specifically details five different
12、 configurations of coiled tubing. The configurations detailed herein should be compatible with pressure levels up to 8000 psi (55.2 MPa) upon completion of analysis for the actual stress and life requirement of the intended application. Formal qualification tests are recommended to verify satisfacto
13、ry installation, clamping, and the life of each unique design. NOTE: For information on design of coiled tube assemblies using CRES steel tubing, see ARP584. 1.1 Purpose The purpose of this document is to provide data and information relative to design, fabrication, and installation of formed tubing
14、 made from titanium alloy. The formed tubing has the function of accepting relative motion between two points in a hydraulic system. 1.2 Field of Application The use of coiled tubes is encouraged in the design of hydraulic systems per AS5440 or ARP4752/ARP4925, and for pneumatic systems per MIL-P-55
15、18 when standard flexible hoses are not feasible due to installation constraints, compliance limitations, and effusion requirements. 2. APPLICABLE DOCUMENTS The following publications form a part of this document to the extent specified herein. The latest issue of SAE publications shall apply. The a
16、pplicable issue of other publications shall be the issue in effect on the date of the purchase order. In the event of conflict between the text of this document and references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and
17、regulations unless a specific exemption has been obtained. 2.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. ARP584 Coiled Tubing - Corrosion Resistant Steel,
18、 Hydraulic Applications, Aerospace AIR1379 Prestressing (Autofrettaging) of Hydraulic Tubing Lines AS4076 Contractile Strain Ratio Testing of Titanium Hydraulic Tubing AS4401 Separable Fittings, Permanent Fittings, Tubing, Fluid Systems, 8000 psi, Qualification Test Standard for AS4467 Standardizati
19、on, Hydraulic Tube Walls ARP4752 Aerospace - Design and Installation of Commercial Transport Aircraft Hydraulic Systems ARP4925 Aerospace - Design and Installation of Commercial Transport Helicopter Hydraulic Systems AS5440 Hydraulic Systems, Military Aircraft, Design and Installation, Requirements
20、For AMS4945 Titanium Alloy Tubing, Seamless, Hydraulic, 3Al - 2.5V, Controlled Contractile Strain Ratio, Cold Worked, Stress Relieved SAE ARP4146C Page 4 of 43 2.2 U.S. Government Publications Available from the Document Automation and Production Service (DAPS), Building 4D, 700 Robbins Avenue, Phil
21、adelphia, PA 19111-5094, Tel: 215-697-9495, https:/assist.daps.dla.mil/quicksearch/. MIL-P-5518 Pneumatic Systems, Aircraft, Design and Installation, General Requirements for MMPDS Metallic Materials Properties Development and Standardization 3. CONFIGURATIONS There are five configurations detailed
22、in this ARP, which are as follows: a. Style A - Helical Torsion Configuration b. Style B - Torsion Tube Configuration c. Style C - Helical Compression/Extension Configuration d. Style D Tri-Coil Compression/Extension Configuration e. Style E- Oval Compression/Extension Configuration Each configurati
23、on is described in the following sections. 3.1 Style A - Helical Torsion Configuration This configuration (Figure 1) typically consists of a 540 degree (1-1/2 coil) helical coil of tubing with a straight section projecting from each end of the coil. The upper illustration in Figure 1 shows an instal
24、lation with the tubing coming from the rod end of the actuator and the coiled tubing not only provides the required flexibility, but also enables the direction of the tube routing to be reversed. The bottom illustration shows an installation where the tubing is coming directly on to the actuators po
25、rt. In the actual application, if the coil is properly clamped at the points defined as “1“ on Figure 1, the tube may have additional bends and straight lengths to allow aligning the end fittings with the interfacing fittings. In practice Style A may vary from 180 degrees (1/2 coil) up to 900 degree
26、s (2-1/2 coils) where the angles quoted are the total angles through which the tubing is bent in the manufacture of each coil. This style is widely used within the aerospace industry to accept angular motion about a defined pivot point. Appendix A contains design data for Style A coiled tubes for 30
27、00 psi (20.7 MPa) to 8000 psi (55.2 MPa), 1/2 to 2-1/2 coils and deflection up to 28 degrees. SAE ARP4146C Page 5 of 43 FIGURE 1 - STYLE A - HELICAL TORSION CONFIGURATION SAE ARP4146C Page 6 of 43 3.2 Style B - Torsion Tube Configuration This configuration (Figure 2) consists of three straight secti
28、ons separated by two 90 degrees bends. This is not a coiled tube configuration but is included in this document to present all standard configurations used to accept relative motion between two points. The middle straight section is twisted in operation, allowing one end to rotate about the centerli
29、ne of the middle straight section. This configuration must be clamped between the bends and the fittings to remove bending stress from the fittings. This configuration is used to accept angular motion about a defined pivot point. FIGURE 2 - STYLE B - TORSION TUBE CONFIGURATION SAE ARP4146C Page 7 of
30、 43 3.3 Style C - Helical Compression/Extension Configuration This configuration (Figure 3) consists of one or more coils coiled in a helix that accepts linear extension and compression. In order to align the coil fittings with the hydraulic component fittings, the use of specific transition bends f
31、rom the tangent of the helix to the end fittings as described later in this document is recommended. FIGURE 3 - STYLE C - HELICAL COMPRESSION/EXTENSION CONFIGURATION SAE ARP4146C Page 8 of 43 3.4 Style D - Tri-Coil Compression/Extension Configuration This configuration (Figure 4) consists of three s
32、ets of helically wound coils connected by straight lengths to allow linear motion between the end fittings. FIGURE 4 - STYLE D - TRI-COIL COMPRESSION/EXTENSION CONFIGURATION SAE ARP4146C Page 9 of 43 3.5 Style E - Oval Compression/Extension Configuration This configuration (Figure 5) is a special ca
33、se of Style C where instead of coils being wound about a helix of constant diameter, the coils are oval shaped with straight lengths between semi-circular coils. This configuration has the advantage of being able to fit into shallow envelopes or to be installed coaxially around the outside of the mo
34、ving hydraulic component for space efficiency. Another advantage of this configuration is that it requires fewer coils because of the large effective diameter of the coils. FIGURE 5 - STYLE E - OVAL HELICAL COMPRESSION/EXTENSION CONFIGURATION SAE ARP4146C Page 10 of 43 4. MATERIAL PROPERTIES The rec
35、ommended material is seamless titanium alloy tubing, Ti-3Al-2.5V in the CWSR condition in accordance with AMS4945 or equivalent. 4.1 Basic Allowables Room temperature allowables for this material are: a. Ultimate tensile strength, Ftu(min): 125 000 psi (862 MPa) b. Yield tensile strength, Fty(min):
36、105 000 psi (724 MPa) c. Elastic modulus, E: 15 000 000 psi (103 421 MPa) d. Torsion modulus, G: 5 680 000 psi (39 162 MPa) e. Poissons ratio, : 0.32 4.2 Endurance Allowables In the design of the various configurations for a specific fatigue life, the use of the correct allowable stress is critical
37、to the life of the design. Specific tests should be conducted on instrumented coils of the configuration to be used in order to determine the allowable number of mechanical flexure cycles at each stress level. The data may be put into the form of a Goodman constant life diagram in order to be easily
38、 used. Ideally, for Styles A and D, planar flexure of curved tubing would give equivalent fatigue data. For Style B, torsion flexure of straight tubing is recommended. For Styles C and E, torsion flexure of curved tubing or rotary flexure of curved tubing would give reasonable fatigue data. If the t
39、ests to determine fatigue life of specimens are conducted at room temperature, the stress allowable determined at each level of cycles should be reduced by an appropriate factor when designing coils which would have to operate in an environment at a higher temperature than the test temperature. A co
40、nservative method of correcting for property reduction at elevated temperature is to ratio the tensile yield stress at the elevated temperature to the tensile yield stress at the test temperature. This is achieved by multiplying the fatigue allowable at the test temperature times the ratio. Temperat
41、ure correction data for several titanium alloys are published in MIL-HDBK-5. Basic S-N curve type summation flexure and impulse fatigue data on straight tubing, bent tubing, and tube/fitting joints is required in sufficient quantity to establish a true performance scatter band to a 0.9 confidence le
42、vel. This data may be obtained from the tube/fitting qualification test program similar to AS4401. From this data, modified Goodman (constant life) diagrams for the tube/fitting should be prepared using the low end of the scatter band (i.e., that S-N curve which represents a 99.9% certainty that all
43、 performance data points that lie on or below the curve represent non failure conditions) as the basis for preparing the diagram. 4.3 Contractile Strain Ratio During tubing fabrication, crystallographic textures that develop in alpha titanium alloys such as Ti-3Al-2.5V CWSR as a result of cold reduc
44、tion can cause significant anisotropy or directional properties in finished tubing. These directional properties manifest themselves as excessive thinning or the rupture of the tube wall on the outer bend radius during bending. Other manifestations are reduced yield and burst strength under internal
45、 pressurization and reduced fatigue life in pressure-flexure testing. The material properties to give a balance of performance between the extremes may be determined using a test property called contractile strain ratio (CSR). AS4076 (referenced in AMS4945) gives a method for determining the CSR. SA
46、E ARP4146C Page 11 of 43 5. STRESS ANALYSIS There are a number of methods that may be used to analyze the total stresses at critical points in the coils, including: a. Von-Mises Distortion Energy Failure Theory for loading in multiple axes. b. Finite Element Analysis (FEA) is another technique for s
47、tress analysis of the sometimes irregular configurations required of coiled tubing. Any FEA software that is used should have bar elements for possible nonlinear cases. 6. FITTINGS The following fitting systems have been tested or used with coiled tube installations successfully: a. MS flareless b.
48、Flareless with brazed or swaged sleeve c. Dynamic beam seal with internal swaging d. Dynamic beam seal with external swaging e. Cryogenic swaged These currently used fitting systems will work with coiled tubing under the following conditions which must be considered in the design. The stresses at th
49、e end of the fittings should be separately analyzed as they may be higher than those in the coils. Any combinations of torsion and linear loading should be avoided unless specifically addressed in the qualification testing of coiled tube designs.7. FABRICATION 7.1 Style A Style A coiled tubing may be fabricated using one of several methods of forming the coils. The use of mandrels or rollers which closely match the tubing outer diameter
