Pub Date : 2020-03-31DOI: 10.62913/engj.v57i1.1161
James A. Swanson, G. Rassati, Chad M. Larson
Structural engineers and detailers are often removed from the process of manufacturing bolts, and thus the tolerances and variances that go along with common manufacturing processes. While this does not represent a problem in most cases, being familiar with the manufacturing processes and tolerances associated with high-strength bolts can help prevent some problems from occurring before the design process even begins, particularly when shorter bolt lengths are needed. This lack of familiarity, in some circumstances, might lead to mistaken assumptions regarding the location of the shear plane relative to the threads of the bolt, which may lead to incorrect designs. While an engineer might presume that bolt strength would not control in such short grips, this paper will discuss the cases in which this can become an issue. This paper summarizes the major variances between nominal and actual dimensions, evaluates some of the consequences that those variances can have on design, presents solutions to those issues, and culminates with a proposed design procedure for proper length determination of high-strength bolts with several illustrative examples.
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Pub Date : 2020-03-31DOI: 10.62913/engj.v57i1.1159
Akashdeep A. Bhat, P. J. Fortney
This paper presents an evaluation of the shear lag factor for HSS tension members connected with two side plate gussets with longitudinal welds as given in AISC Specification Table D3.1, Case 6b. The current AISC Specification for Case 6b does not permit weld lengths less than the perpendicular distance between the welds, and has the potential of producing negative shear lag factors. Similar issues previously existed for members given in Case 4 of Table D3.1. However, the AISC Specification has adopted a mathematical model proposed by Fortney and Thornton for Case 4 of Table D3.1. The work presented in this paper offers: (1) a mathematical model for calculating the shear lag factor for Case 6b derived by repurposing the model adopted by AISC for Case 4 of Table D3.1; (2) the results of a parametric study comparing the results of the new mathematical model to the results using the current AISC method, and; (3) discusses the protocols developed for use in finite element analysis to evaluate the effectiveness of the proposed mathematical model. The proposed new mathematical model will permit longitudinal weld lengths less than the perpendicular distance between the welds, and removes the possibility of calculating a negative shear lag factor, while better representing the redistribution of cross-sectional stress near the connection region.
{"title":"Reexamination of Shear Lag in HSS Tension Members with Side Gusset Plate Connections","authors":"Akashdeep A. Bhat, P. J. Fortney","doi":"10.62913/engj.v57i1.1159","DOIUrl":"https://doi.org/10.62913/engj.v57i1.1159","url":null,"abstract":"This paper presents an evaluation of the shear lag factor for HSS tension members connected with two side plate gussets with longitudinal welds as given in AISC Specification Table D3.1, Case 6b. The current AISC Specification for Case 6b does not permit weld lengths less than the perpendicular distance between the welds, and has the potential of producing negative shear lag factors. Similar issues previously existed for members given in Case 4 of Table D3.1. However, the AISC Specification has adopted a mathematical model proposed by Fortney and Thornton for Case 4 of Table D3.1. The work presented in this paper offers: (1) a mathematical model for calculating the shear lag factor for Case 6b derived by repurposing the model adopted by AISC for Case 4 of Table D3.1; (2) the results of a parametric study comparing the results of the new mathematical model to the results using the current AISC method, and; (3) discusses the protocols developed for use in finite element analysis to evaluate the effectiveness of the proposed mathematical model. The proposed new mathematical model will permit longitudinal weld lengths less than the perpendicular distance between the welds, and removes the possibility of calculating a negative shear lag factor, while better representing the redistribution of cross-sectional stress near the connection region.","PeriodicalId":11618,"journal":{"name":"Engineering Journal","volume":" 61","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141219527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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