1、American Welding Society Design Handbook for Calculating DESIGN HANDBOOK for CALCULATING FILLET WELD SIZES Located, reviewed and reformatted under the AWS Product Development Committee as a service for quality-minded welding fabricators. This publication is designed to provide information in regard
2、to the subject matter covered. It is made available with the understanding that the publisher is not engaged in the rendering of professional advice. Reliance upon the information contained in this document should not be undertaken without an independent verification of its application for a particu
3、lar use. The publisher is not responsible for loss or damage resulting from use of this publication. This document is not a consensus standard. Users should refer to the applicable standards for their particular application. American Weldlng Society 550 N.W. LeJeune Road, Miami, Florida 33126 FOREWO
4、RD The design of a welded connection is usually the first operation in the construction of a welded product. The optimiza- tion of the design for the initial manufacturability and the life cycle performance of the component is a challenge to the designer. Fillet welds are the most common joint desig
5、ns in the fabrication of many welded products. The use of fillet welds sim- plifies the material preparation effort and increases the opportunity for using automation in the welding operation. Traditional designs base the size of the welds on the allowable unit loads that the welds are expected to e
6、xperience in the intended applications. For sections of different thicknesses, the minimum fillet size can be governed by the thicker member. While this approach is conservative, the weld sizes may not be the optimum. As the volume of weld metal is severely impacted by the size of the weld, each inc
7、rease in the specified leg length has a dramatic effect on the amount of weld- ing required. An alternative system for calculating fillet weld sizes was presented by two researchers. Selection of the correct fillet weld size is essential for the satisfactory performance of many weldments in service
8、today. Fillet welds are used in vir- tually every industry, and when properly designed, provide effective and efficient connections. An alternate approach to the more traditional design philosophy is the basis for this handbook, and seeks to provide a method for determining the optimum fillet weld s
9、ize. O Copyright 1997 by the American Welding Society. All rights reserved. Printed in the United States of America. ii TABLE OF CONTENTS Foreword ii 1 .O Introduction 1 2.0 Development of Criteria . 1 3.0 Development of Fillet Weld Sizes 3 4.0 Fillet Weld Size Tables 3 5.0 Assumptions 4 6.0 Referen
10、ces 4 Appendix A . 9 Part I - Steel Intercostal Member Ordinary Strength Steel 10 High Strength Steel . 11 Quenched and Tempered Steel (HY 80) . 12 Part II -Austenitic Stainless Steel Intercostal Member Austenitic Stainless Steel 15 Ordinary Strength Steel 15 High Strength Steel . 16 Quenched and Te
11、mpered Steel (HY 80) . 16 Part III - Aluminum Alloy Intercostal Member Aluminum Alloy 5052 16 Aluminum Alloy 5083 18 Aluminum Alloy 5086 20 Aluminum Alloy 5454 21 Aluminum Alloy 5456 23 LIST OF TABLES Table 1 . Base Material Strength Values 5 2 . Filler Material Strength Values . 6 LIST OF FIGURES F
12、igure 1 . Double Fillet Welded Joint Loaded in Longitudinal Shear . 7 2 . Double Fillet Welded joint Loaded in Transverse Shear . 7 iii STD=AWS FWSH-ENGL L997 .I 0784265 0539473 5bB 1 .O INTRODUCTION Selection of the correct fillet weld size is essential for the satisfactory performance of many weld
13、ments in service today. Fillet welds are used in virtually every industry, and when properly designed, provide effective and efficient connections. Traditional designs base the size of the welds on the allowable unit loads that the welds are expected to experience in the intended applications. For s
14、ections of different thick- nesses, the minimum fillet size is governed by the thicker member (references 1 and 2). While this approach is conservative, the weld sizes may not be the optimum. Fillet welds can be too large or too small and it is important to have the correct size for each connection.
15、 As the volume of weld metal is severely impacted by the size of the weld, each increase in the specified fillet weld leg length has a dramatic effect on the amount of welding required. The larger than necessary welds will increase the amount of welding material, reduce the speed of welding, and inc
16、rease the resultant distortion effects. All of these will have a negative impact on the economy of the work and the overall productivity of the operation. Similarly, too small fillet welds will not provide the necessary performance for the weldment and will most likely result in repair work being re
17、quired. An alternative system for calculating fillet weld sizes was presented by two research- ers through reference 3. This approach is the basis for this handbook, and seeks to provide a method for determining the optimum fillet weld size. This document is not a standard. 2.0 DEVELOPMENT As the st
18、rength and ductility of fillet welded joints varies as a function of the loading OF CRITERIA direction, design equations must be developed for both longitudinal and transverse shear loads. It is also fundamentally important that the equations be applicable for a wide range of base materials and fill
19、er materials. It is common for all fillet welds to have a combination of longitudinal shear, Figure 1, and transverse shear, Figure 2. For design purposes, bending moments should be similar to transverse loading on the fillet welds. It is common in structural design for the intercostal member to be
20、the “weaker“ member in the joint. For these cases, the longitudinal shear connection need only develop the ultimate shear strength of the intercostal member, and the transverse shear connection must develop the ultimate tensile of strength of the intercostal member. When welds are designed for these
21、 load- ing conditions, they are normally adequate for the variety of combinations of shear and tension loads that a member can sustain. Traditionally, fillet weld size is based upon the thickness of the “weaker“ member and two mechanical properties, the ultimate tensile strength of the base material
22、, and the longitudinal shear strength of the weld material. The alternate method, presented in this handbook, requires six equations and four mechanical properties, the same two as before, plus the ultimate shear strength of the base material and the transverse shear strength of the weld material fo
23、r the intercostal member. A similar set of equa- tions is required for the continuous member. AWS Design Handbook 1 For each fillet weld connection, there can be a failure in one of three locations in the weld zone: l. Failure through the throat (ignoring bead reinforcement or penetration). 2. Failu
24、re in the heat affected zone of the intercostal member. 3. Failure in the heat affected zone of the continuous member. Based upon the geometrical relationships and the two directions of loading, a series of equations can be developed that will result in a fillet weld size that will provide a load ca
25、rrying capacity equal to either the intercostal or continuous member, .e., a 100% efficient weld. For longitudinal loading: Failure Location Intercostal Member Continuous Member Weld Throat Tl x us, S= 1.414 U, Tc x us, = 0.707 ULS HAZ Boundary (Intercostal) S = 0.454 Tl Tc x us, 1.1 us, S= HAZ Boun
26、dary (Continuous) Tl x us, S=- 2.2 us, S = 0.909 Tc For transverse loading: Failure Location Intercostal Member Continuous Member Weld Throat Tl x TI Tc x us, S= 1.414 U, S= 0.707 U, HAZ Boundary (Intercostal) Tl x TI S=- 2.2 us, Tc x us, 1.1 u, S= HAZ Boundary (Continuous) Tl x UTI Tc x us, S=- 2.0
27、 UTC S= u TC Fillet Weld Size Thickness of Intercostal Member Thickness of Continuous Member Ultimate Tensile Strength of Intercostal Member Longitudinal Shear Strength of Weld Metal Shear Strength of Intercostal Member Transverse Shear Strength of Weld Metal Ultimate Tensile Strength of Continuous
28、Member Shear Strength of Continuous Member 2 AWS Design Handbook STD-AWS FWSH-ENGL L997 m 07842b5 0539475 330 E .O DEVELOPMENT T OF FILLET til WELD SIZES b SI 4.0 FILLET WELD SIZE TABLES S e IT F b ir ir F F C1 tl E ables 1 an 2 provide the mechanical properties required to solve the various equa- o
29、ns. References 4, 5, and 6 are the sources for the majority of the values. For the ase materials that do not have published values for shear strength the following con- ervative estimates have been made: Shear strength = 0.75 x tensile strength (steels) Shear strength = 0.60 x tensile strength (alum
30、inum) 8imilarly, for the filler material values, selected data is not readily available, so mathe- ratical relationships have been used to complete the table. As documented in refer- nce 3, a conservative value for filler metal transverse shear strength is: Transverse shear strength = 1.33 x longitu
31、dinal shear strength or most designs, the intercostal member is the weakest member of the assembly for 0th longitudinal and transverse loads. Exceptions to this include, cases where the ltercostal member is much thicker than the continuous member or the strength of the ltercostal member is much grea
32、ter than that of the continuous member. he tables contained in Appendix A specify the minimum fillet weld size required to rovide a 100% connection for those cases where the intercostal is the weaker mem- er. The sizes were derived by solving the six equations presented in Section 2.0 for le interco
33、stal member. To be conservative, the largest calculated value has been elected as the required weld size. For convenience, the decimal value has been Iunded up to the nearest 1/16 in. dimension. or example, where the intercostal member is high strength steel, 1/4 in. thick, the ontinuous member is h
34、igh strength steel, 1/4 in. thick, and the weld material is i701 8, hen: T, = 1/4 in. Tc = 1/4 in. md from Tables 1 and 2: AWS Design Handbook 3 STD-AWS FWSH-ENGL L977 0784265 051947b 277 m S, = 0.454 (1/4) = 0.01 1 (1 /4) (56250) 3 = 2.2 (56250) = 0.011 (1/4) (75000) 5 = 2.2 (56250) = 0.150 (1 /4)
35、(75000) 6 = 2.0 (75000) = 0.125 Therefore, the controlling size is 0.1 70 or 3/16. 5.0 ASSUMPTIONS The fillet weld sizes presented in Appendix A are only valid for 100% efficient double continuous fillet welds. For designs that require unequal fillet legs or require skewed fillet weld connections, a
36、lternate sources of information are required. Also, the values presume that the intercostal member will always be the weaker mem- ber of the design. As this is true in the great majority of structural designs, the tables have been constructed accordingly. For those designs having the continuous memb
37、er as the weaker member, the formulas contained in Section 2.0 for the continuous mem- ber may be used to calculate the optimum fillet weld size. The data presented in Appendix A must be used with correct welding procedures. It is understood that the joining of the materials is controlled by an appr
38、opriate welding procedure. Considerations of the essential elements of welding procedures, and other essential features required for a specific weld application, are not incorporated in the derivation of the weld tables. 6.0 REFERENCES l. Welding Handbook, Volume 1, Eighth Edition, American Welding
39、Society, 1987. 2. Welding Handbook, Volume 5, Seventh Edition, American Welding Society, 1984. 3. “Reduced Fillet Weld Sizes for Naval Ships,” R.P. Krumken, Jr. and C.R. Jordan, Welding Journal, American Welding Society, April 1984. 4. MIL-STD-1628, Fillet Weld Size, Strength and Efficiency Determin
40、ation, June 1974. 5. “Evaluation of Fillet Weld Shear Strength of FCAW Electrodes,” Welding Journal, American Welding Society, August 1989. 6. Mare Island Naval Shipyard Technical Report 138-4-80, Revision A, December 1980. 4 AWS Design Handbook Table l. BASE MATERIAL STRENGTH VALUES Minimum Ultimat
41、e Base Material Type Tensile Strength (psi) Shear Strength (psi) Quenched and Tempered 11 4,000 85,500 Alloy Steel (HY-100) Quenched and Tempered 96,000 72,000 Alloy Steel (HY-80) High Strength Steel (A588) 75,000 56,250 Ordinary Strength Steel 60,000 45,000 0436) Austenitic Stainless Steel 75,000 5
42、6,250 Nickel Copper Alloy 70,000 46,000 Nickel Chromium Iron 80,000 57,000 Aluminum Alloy 5456 45,000 27,000 Aluminum Alloy 5454 36,000 2 1,600 Aluminum Alloy 5086 38,000 22,800 Aluminum Alloy 5083 40,000 24,000 Aluminum Alloy 5052 25,000 15,000 Copper Nickel (70/30) 45,000 22,500 Copper Nickel (90/
43、1 O) 40,000 20,000 AWS Design Handbook 5 Table 2. FILLER MATERIAL STRENGTH VALUES Minimum Average Average Ultimate Tensile Longitudinal Shear Transverse Shear TY Pe Strength (ksi) Strength (ksi) Strength (ksi) E11018M 110 79 105 El O01 8M 1 O0 72 99 E901 8M 90 69 91 E801 8 80 62 82 E701 8 70 59 78 E
44、601 O 62 49 65 E309 80 58 77 E31 6 70 61 81 ENiCrFe-3 80 61 81 ECuNi 50 45 60 Bare Electrodes ENiCu-7 70 60 80 ER120S-1 ER100S-1 ER70S-X ER309 ER316L ERNiCr-3 ERCuNi ERCuSi ER5356 ER5556 ER4043 ER1100 ERNCU-7 120 1 O0 70 80 70 80 70 50 50 35 42 24 11 87 83 59 67 61 55 53 45 18 22 24 13 7 116 99 78 8
45、9 81 73 70 60 24 29 31 17 9 Flux Cored Electrodes ElOlTl 1 O0 E71T1 70 74 64 103 85 6 AWS Design Handbook Figure 1. DOUBLE FILLET WELDED JOINT LOADED IN LONGITUDINAL SHEAR Figure 2. DOUBLE FILLET WELDED JOINT LOADED IN TRANSVERSE SHEAR INTERCOSTAL r INTERCOS #TAL AWS Design Handbook 7 APPENDIX A The
46、 values contained in the following tables are based upon the following statements: l. The equations contained in Section 2.0 for the intercostal member being the weaker member have been used to develop the weld sizes. 2. The sizes shown in the tables are for 100% efficient double continuous fillet w
47、elds and do not include welds with uneven legs or skewed welds. 3. The maximum calculated size determined by the Section 2.0 formulas was selected in each case. The actual calculated decimal value was rounded up to the nearest 1/16 in. for presentation in the table. 4. It was assumed that 1/8 in. wa
48、s the smallest weld size to be considered. For each case having the maximum calculated value to be less than 0.124 in., the optimum weld size was selected to be 1/8 in. AWS Design Handbook 9 PART I - STEEL Table Al Intercostal Member: Ordinary Strength Steel Continuous Member: Ordinary Strength Stee
49、l - Electrode Type Intercostal Thickness E601 O E701 8 E801 8 ER70S-X E71T-1 1 I0 1 10 1 /0 1 I0 1 /0 1 I0 1 I4 311 6 311 6 311 6 311 6 311 6 318 1 I4 114 1 14 1 14 1 I4 1 12 310 511 6 511 6 511 6 511 6 510 7/16 711 6 711 6 7/16 711 6 314 1 12 1 12 1 12 1 /2 1 12 Table A2 Intercostal Member: Ordinary Strength Steel Continuous Member: High Strength Steel Electrode Type Intercostal Thickness E601 O E701 8 E801 8 ER70S-X E71T-1 1 I8 1 I8 1 /8 1 /0 1 /a 1 18 1 I4 311 6 311 6 311 6 311 6 311 6 310 1 I4 1 I4 1 /4 1 I4 1 I4 1 12 318 511 6 5/16 511 6 511 6 510 711 6 7
