{"id":133,"date":"2018-02-07T14:13:54","date_gmt":"2018-02-07T19:13:54","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/powr4406\/?post_type=chapter&#038;p=133"},"modified":"2018-06-25T11:56:32","modified_gmt":"2018-06-25T15:56:32","slug":"bolted-and-welded-joints","status":"publish","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/powr4406\/chapter\/bolted-and-welded-joints\/","title":{"raw":"Bolted and Welded Joints","rendered":"Bolted and Welded Joints"},"content":{"raw":"<div class=\"bcc-box bcc-highlight\">\r\n<h3 itemprop=\"educationalUse\"><strong>Learning Objectives<\/strong><\/h3>\r\nAt the end of this section you will be able to\r\n<ul>\r\n \t<li>calculate the allowable load of bolted lap joints<\/li>\r\n \t<li>calculate the allowable load of welded joints<\/li>\r\n<\/ul>\r\n<\/div>\r\n<div class=\"textbox shaded\" style=\"text-align: center\"><strong>Bolted joints<\/strong><\/div>\r\nTwo end plates bolted together and subject to symmetrical tensile loads react to the applied forces through the shear resistance of the bolts <span style=\"text-decoration: underline\">and<\/span> the friction force developed between the plates.\u00a0 The friction force is difficult to evaluate since it depends on the relative roughness of the contact surface and may also be affected by environmental changes (bolts thermal expansion reduces the friction force).\u00a0 As a result, conservative load calculations rely only on the shear resistance of the bolts (or rivets);\u00a0 the extra joint capacity due to friction increases the safety factor.\r\n\r\nThere are various scenarios that may lead to bolted joints failure, all described in the textbook.\u00a0 When completing these calculations please note the following:\r\n<ul>\r\n \t<li>nomenclature is listed in the textbook on page 6.<\/li>\r\n \t<li>material properties are taken from Textbook Appendices B3 and B4<\/li>\r\n<\/ul>\r\nThe following is a summary of the required calculations.\u00a0 The lowest value represents the maximum allowable load.\r\n\r\n<span style=\"text-decoration: underline\">Shear Failure of the bolts<\/span>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <em><strong>P<sub>s <\/sub>= n\u00d7A<sub>B<\/sub>\u00d7\u03c4<sub>all<\/sub>\u00d7N<\/strong><\/em>\r\n<ul>\r\n \t<li>\u03c4<sub>all<\/sub>, allowable bolt shear stress depends on the the shear location; this can be along the threaded section or the smooth section of the bolt.<\/li>\r\n<\/ul>\r\n<span style=\"text-decoration: underline\">Bearing Failure of the Plates<\/span>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <em><strong>P<sub>P <\/sub>= d\u00d7t\u00d7\u03c3<sub>-all<\/sub>\u00d7N<\/strong><\/em>\r\n<ul>\r\n \t<li>\u03c3<sub>-all<\/sub>, allowable bearing stress is 1.5 times the ultimate tensile strength of the plate material.<\/li>\r\n<\/ul>\r\n<span style=\"text-decoration: underline\">Gross Tensile Failure of the Plates<\/span>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <em><strong>P<sub>G <\/sub>= b\u00d7t\u00d7\u03c3<sub>G-all<\/sub><\/strong><\/em>\r\n<ul>\r\n \t<li>\u03c3<sub>G-all<\/sub>, allowable gross tensile stress of the plate is 60% of the yield strength of the material<\/li>\r\n<\/ul>\r\n<span style=\"text-decoration: underline\">Net Tensile Failure of the Plates<\/span>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <em><strong>P<sub>N <\/sub>= (b\u00d7t-N<sub>F<\/sub>\u00d7d<sub>H<\/sub>\u00d7t)\u00d7\u03c3<sub>N-all<\/sub><\/strong><\/em>\r\n<ul>\r\n \t<li>\u03c3<sub>N-all<\/sub>, allowable net tensile stress is half of the ultimate tensile strength of the plate material<\/li>\r\n<\/ul>\r\n<div class=\"textbox shaded\" style=\"text-align: center\"><strong>Welded joints<\/strong><\/div>\r\nWelded joints are often preferred to bolted joints because they are simpler, easier to complete, relatively stronger and can provide a sealed assembly. However, they cannot be dismantled for maintenance or replacing parts.\r\n\r\nWhen completing weld calculations please note the following:\r\n<ul>\r\n \t<li>nomenclature is listed in the textbook on page 6.<\/li>\r\n \t<li>use Appendix B6 for common weld and plate size; use Appendix B5 for weld strength of common electrodes<\/li>\r\n<\/ul>\r\n<span style=\"text-decoration: underline\">Weld Strength\u00a0<\/span>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <em><strong>P<sub>weld <\/sub>= L\u00d7f<sub>weld<\/sub><\/strong><\/em>\r\n\r\n<span style=\"text-decoration: underline\">Gross Tensile Strength of the Plates<\/span> - \u00a0 same as for bolted joints\r\n<div class=\"bcc-box bcc-info\">\r\n<h3 itemprop=\"educationalUse\"><strong>Assigned Problems<\/strong> \u00a0 [footnote]From Problem Set - Spring 2017, by Barry Dupen[\/footnote]<\/h3>\r\n<\/div>\r\n<strong>Problem 1: <\/strong>Two A992 steel plates are joined with two A992 steel splice plates and twelve 1 in. diameter A490 steel bolts with threads in the shear planes. Calculate the maximum load that the joint can support, in kips.\r\n\r\n<img src=\"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig1.jpg\" alt=\"\" class=\"alignnone size-full wp-image-210\" width=\"730\" height=\"321\" \/>\r\n\r\n<strong>Problem 2: <\/strong>Two A36 steel plates form a lap joint with four 20 mm diameter A307 steel bolts. Calculate the maximum load that the joint can support, in kips.\r\n\r\n<img src=\"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig2.jpg\" alt=\"\" class=\"alignnone size-full wp-image-211\" width=\"735\" height=\"275\" \/>\r\n\r\n<strong>Problem 3: <\/strong>Two A36 steel plates are welded with an E70 electrode.\r\n<ul>\r\n \t<li>What is the minimum recommended weld size for this joint? [in.]<\/li>\r\n \t<li>What is the joint strength? [kips]<\/li>\r\n<\/ul>\r\n<img src=\"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig3.jpg\" alt=\"\" class=\"alignnone size-full wp-image-212\" width=\"639\" height=\"354\" \/>\r\n\r\n<strong>Problem 4: <\/strong>Two A36 steel plates are welded as shown with a 3\/8 in. fillet weld using an E60 electrode. What is the joint strength?\r\n\r\n<img src=\"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig4.jpg\" alt=\"\" class=\"alignnone size-full wp-image-213\" width=\"630\" height=\"310\" \/>\r\n\r\n<strong>Problem 5: <\/strong>Suggest on improvement to this chapter.\r\n\r\n&nbsp;\r\n\r\n&nbsp;\r\n\r\n&nbsp;\r\n\r\n&nbsp;\r\n\r\n&nbsp;\r\n\r\n&nbsp;\r\n\r\n&nbsp;\r\n\r\n&nbsp;\r\n\r\n&nbsp;","rendered":"<div class=\"bcc-box bcc-highlight\">\n<h3 itemprop=\"educationalUse\"><strong>Learning Objectives<\/strong><\/h3>\n<p>At the end of this section you will be able to<\/p>\n<ul>\n<li>calculate the allowable load of bolted lap joints<\/li>\n<li>calculate the allowable load of welded joints<\/li>\n<\/ul>\n<\/div>\n<div class=\"textbox shaded\" style=\"text-align: center\"><strong>Bolted joints<\/strong><\/div>\n<p>Two end plates bolted together and subject to symmetrical tensile loads react to the applied forces through the shear resistance of the bolts <span style=\"text-decoration: underline\">and<\/span> the friction force developed between the plates.\u00a0 The friction force is difficult to evaluate since it depends on the relative roughness of the contact surface and may also be affected by environmental changes (bolts thermal expansion reduces the friction force).\u00a0 As a result, conservative load calculations rely only on the shear resistance of the bolts (or rivets);\u00a0 the extra joint capacity due to friction increases the safety factor.<\/p>\n<p>There are various scenarios that may lead to bolted joints failure, all described in the textbook.\u00a0 When completing these calculations please note the following:<\/p>\n<ul>\n<li>nomenclature is listed in the textbook on page 6.<\/li>\n<li>material properties are taken from Textbook Appendices B3 and B4<\/li>\n<\/ul>\n<p>The following is a summary of the required calculations.\u00a0 The lowest value represents the maximum allowable load.<\/p>\n<p><span style=\"text-decoration: underline\">Shear Failure of the bolts<\/span>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <em><strong>P<sub>s <\/sub>= n\u00d7A<sub>B<\/sub>\u00d7\u03c4<sub>all<\/sub>\u00d7N<\/strong><\/em><\/p>\n<ul>\n<li>\u03c4<sub>all<\/sub>, allowable bolt shear stress depends on the the shear location; this can be along the threaded section or the smooth section of the bolt.<\/li>\n<\/ul>\n<p><span style=\"text-decoration: underline\">Bearing Failure of the Plates<\/span>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <em><strong>P<sub>P <\/sub>= d\u00d7t\u00d7\u03c3<sub>-all<\/sub>\u00d7N<\/strong><\/em><\/p>\n<ul>\n<li>\u03c3<sub>-all<\/sub>, allowable bearing stress is 1.5 times the ultimate tensile strength of the plate material.<\/li>\n<\/ul>\n<p><span style=\"text-decoration: underline\">Gross Tensile Failure of the Plates<\/span>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <em><strong>P<sub>G <\/sub>= b\u00d7t\u00d7\u03c3<sub>G-all<\/sub><\/strong><\/em><\/p>\n<ul>\n<li>\u03c3<sub>G-all<\/sub>, allowable gross tensile stress of the plate is 60% of the yield strength of the material<\/li>\n<\/ul>\n<p><span style=\"text-decoration: underline\">Net Tensile Failure of the Plates<\/span>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <em><strong>P<sub>N <\/sub>= (b\u00d7t-N<sub>F<\/sub>\u00d7d<sub>H<\/sub>\u00d7t)\u00d7\u03c3<sub>N-all<\/sub><\/strong><\/em><\/p>\n<ul>\n<li>\u03c3<sub>N-all<\/sub>, allowable net tensile stress is half of the ultimate tensile strength of the plate material<\/li>\n<\/ul>\n<div class=\"textbox shaded\" style=\"text-align: center\"><strong>Welded joints<\/strong><\/div>\n<p>Welded joints are often preferred to bolted joints because they are simpler, easier to complete, relatively stronger and can provide a sealed assembly. However, they cannot be dismantled for maintenance or replacing parts.<\/p>\n<p>When completing weld calculations please note the following:<\/p>\n<ul>\n<li>nomenclature is listed in the textbook on page 6.<\/li>\n<li>use Appendix B6 for common weld and plate size; use Appendix B5 for weld strength of common electrodes<\/li>\n<\/ul>\n<p><span style=\"text-decoration: underline\">Weld Strength\u00a0<\/span>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 <em><strong>P<sub>weld <\/sub>= L\u00d7f<sub>weld<\/sub><\/strong><\/em><\/p>\n<p><span style=\"text-decoration: underline\">Gross Tensile Strength of the Plates<\/span> &#8211; \u00a0 same as for bolted joints<\/p>\n<div class=\"bcc-box bcc-info\">\n<h3 itemprop=\"educationalUse\"><strong>Assigned Problems<\/strong> \u00a0 <a class=\"footnote\" title=\"From Problem Set - Spring 2017, by Barry Dupen\" id=\"return-footnote-133-1\" href=\"#footnote-133-1\" aria-label=\"Footnote 1\"><sup class=\"footnote\">[1]<\/sup><\/a><\/h3>\n<\/div>\n<p><strong>Problem 1: <\/strong>Two A992 steel plates are joined with two A992 steel splice plates and twelve 1 in. diameter A490 steel bolts with threads in the shear planes. Calculate the maximum load that the joint can support, in kips.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig1.jpg\" alt=\"\" class=\"alignnone size-full wp-image-210\" width=\"730\" height=\"321\" srcset=\"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig1.jpg 730w, https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig1-300x132.jpg 300w, https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig1-65x29.jpg 65w, https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig1-225x99.jpg 225w, https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig1-350x154.jpg 350w\" sizes=\"auto, (max-width: 730px) 100vw, 730px\" \/><\/p>\n<p><strong>Problem 2: <\/strong>Two A36 steel plates form a lap joint with four 20 mm diameter A307 steel bolts. Calculate the maximum load that the joint can support, in kips.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig2.jpg\" alt=\"\" class=\"alignnone size-full wp-image-211\" width=\"735\" height=\"275\" srcset=\"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig2.jpg 735w, https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig2-300x112.jpg 300w, https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig2-65x24.jpg 65w, https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig2-225x84.jpg 225w, https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig2-350x131.jpg 350w\" sizes=\"auto, (max-width: 735px) 100vw, 735px\" \/><\/p>\n<p><strong>Problem 3: <\/strong>Two A36 steel plates are welded with an E70 electrode.<\/p>\n<ul>\n<li>What is the minimum recommended weld size for this joint? [in.]<\/li>\n<li>What is the joint strength? [kips]<\/li>\n<\/ul>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig3.jpg\" alt=\"\" class=\"alignnone size-full wp-image-212\" width=\"639\" height=\"354\" srcset=\"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig3.jpg 639w, https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig3-300x166.jpg 300w, https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig3-65x36.jpg 65w, https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig3-225x125.jpg 225w, https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig3-350x194.jpg 350w\" sizes=\"auto, (max-width: 639px) 100vw, 639px\" \/><\/p>\n<p><strong>Problem 4: <\/strong>Two A36 steel plates are welded as shown with a 3\/8 in. fillet weld using an E60 electrode. What is the joint strength?<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig4.jpg\" alt=\"\" class=\"alignnone size-full wp-image-213\" width=\"630\" height=\"310\" srcset=\"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig4.jpg 630w, https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig4-300x148.jpg 300w, https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig4-65x32.jpg 65w, https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig4-225x111.jpg 225w, https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-content\/uploads\/sites\/290\/2018\/02\/Ch6Fig4-350x172.jpg 350w\" sizes=\"auto, (max-width: 630px) 100vw, 630px\" \/><\/p>\n<p><strong>Problem 5: <\/strong>Suggest on improvement to this chapter.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<hr class=\"before-footnotes clear\" \/><div class=\"footnotes\"><ol><li id=\"footnote-133-1\">From Problem Set - Spring 2017, by Barry Dupen <a href=\"#return-footnote-133-1\" class=\"return-footnote\" aria-label=\"Return to footnote 1\">&crarr;<\/a><\/li><\/ol><\/div>","protected":false},"author":239,"menu_order":10,"template":"","meta":{"pb_show_title":"on","pb_short_title":"Joints","pb_subtitle":"Joints","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[57],"license":[],"class_list":["post-133","chapter","type-chapter","status-publish","hentry","contributor-alex-podut"],"part":3,"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-json\/pressbooks\/v2\/chapters\/133","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-json\/wp\/v2\/users\/239"}],"version-history":[{"count":17,"href":"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-json\/pressbooks\/v2\/chapters\/133\/revisions"}],"predecessor-version":[{"id":572,"href":"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-json\/pressbooks\/v2\/chapters\/133\/revisions\/572"}],"part":[{"href":"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-json\/pressbooks\/v2\/parts\/3"}],"metadata":[{"href":"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-json\/pressbooks\/v2\/chapters\/133\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-json\/wp\/v2\/media?parent=133"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-json\/pressbooks\/v2\/chapter-type?post=133"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-json\/wp\/v2\/contributor?post=133"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/powr4406\/wp-json\/wp\/v2\/license?post=133"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}