{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T02:09:09Z","timestamp":1760148549385,"version":"build-2065373602"},"reference-count":36,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2023,5,17]],"date-time":"2023-05-17T00:00:00Z","timestamp":1684281600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004829","name":"Sichuan Science and Technology Program","doi-asserted-by":"publisher","award":["2020YJ0307"],"award-info":[{"award-number":["2020YJ0307"]}],"id":[{"id":"10.13039\/501100004829","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Bolted spherical joints, due to their prominent merits in installation, have been widely used in modern spatial structures. Despite significant research, there is a lack of understanding of their flexural fracture behaviour, which is important for the catastrophe prevention of the whole structure. Given the recent development to fill this knowledge gap, it is the objective of this paper to experimentally investigate the flexural bending capacity of the overall fracture section featured by a heightened neutral axis and fracture behaviour related to variable crack depth in screw threads. Accordingly, two full-scale bolted spherical joints with different bolt diameters were evaluated under three-point bending. The fracture behaviour of bolted spherical joints is first revealed with respect to typical stress distribution and fracture mode. A new theoretical flexural bending capacity expression for the fracture section with a heightened neutral axis is proposed and validated. A numerical model is then developed to estimate the stress amplification and stress intensity factors related to the crack opening (mode-I) fracture for the screw threads of these joints. The model is validated against the theoretical solutions of the thread-tooth-root model. The maximum stress of the screw thread is shown to take place at the same location as the test bolted sphere, while its magnitude can be greatly reduced with an increased thread root radius and flank angle. Finally, different design variants related to threads that have influences on the SIFs are compared, and the moderate steepness of the flank thread has been found to be efficient in reducing the joint fracture. The research findings could thus be beneficial for further improving the fracture resistance of bolted spherical joints.<\/jats:p>","DOI":"10.3390\/ma16103781","type":"journal-article","created":{"date-parts":[[2023,5,18]],"date-time":"2023-05-18T07:03:58Z","timestamp":1684393438000},"page":"3781","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Investigation on Flexural Fracture Behaviour of Bolted Spherical Joints with Crack Propagation in Screw Threads"],"prefix":"10.3390","volume":"16","author":[{"given":"Qinghong","family":"Shi","sequence":"first","affiliation":[{"name":"Key Laboratory of Deep Underground Science and Engineering (Ministry of Education), School of Architecture and Environment, Sichuan University, Chengdu 610065, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wenfeng","family":"Zhou","sequence":"additional","affiliation":[{"name":"CREGC Architectural & Construction Engineering Co., Ltd., Chengdu 610031, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiang","family":"You","sequence":"additional","affiliation":[{"name":"Key Laboratory of Deep Underground Science and Engineering (Ministry of Education), School of Architecture and Environment, Sichuan University, Chengdu 610065, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yinggai","family":"Liu","sequence":"additional","affiliation":[{"name":"CREGC Architectural & Construction Engineering Co., Ltd., Chengdu 610031, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhiyu","family":"Wang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Deep Underground Science and Engineering (Ministry of Education), School of Architecture and Environment, Sichuan University, Chengdu 610065, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qunyi","family":"Huang","sequence":"additional","affiliation":[{"name":"College of Civil Engineering, Southwest Jiaotong University, Chengdu 610031, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,5,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1177\/026635119501000304","article-title":"A summary survey of prefabricated spatial frame systems","volume":"10","author":"Hanaor","year":"1995","journal-title":"J. Int. J. Space Struct."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"458","DOI":"10.1016\/j.engfailanal.2007.05.005","article-title":"Experimental and finite element investigations on the collapse of a Mero space truss roof structure\u2014A case study","volume":"15","author":"Caglayan","year":"2007","journal-title":"J. Eng. Fail. Anal."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1016\/j.engfailanal.2015.11.039","article-title":"Partial collapses experienced for a steel space truss roof structure induced by ice ponds","volume":"60","author":"Piroglu","year":"2016","journal-title":"Eng. Fail. Anal."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"601","DOI":"10.1016\/j.jcsr.2016.09.023","article-title":"Mechanical behavior of ring-sleeve joints of single-layer reticulated shells","volume":"128","author":"Feng","year":"2017","journal-title":"J. Constr. Steel Res."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1016\/j.tws.2017.05.007","article-title":"Experimental and numerical studies on single-layer reticulated shells with aluminium alloy gusset joints","volume":"118","author":"Xiong","year":"2017","journal-title":"Thin-Walled Struct."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1550147718759234","DOI":"10.1177\/1550147718759234","article-title":"Connection looseness detection of steel grid structures using piezoceramic transducers","volume":"14","author":"Yan","year":"2018","journal-title":"Int. J. Distrib. Sens. Netw."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"802","DOI":"10.1007\/s13296-018-0029-7","article-title":"Experimental study on residual mechanical properties of bolt-sphere joints after a fire","volume":"18","author":"Liu","year":"2018","journal-title":"Int. J. Steel Struct."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"359","DOI":"10.1016\/j.jcsr.2019.05.032","article-title":"The bearing performance of the bolt-sphere joints with stochastic pitting corrosion damage","volume":"160","author":"Yuan","year":"2019","journal-title":"J. Constr. Steel Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"322","DOI":"10.1016\/j.tws.2019.05.003","article-title":"Mechanical performance of an improved semi-rigid joint system under bending and axial forces for aluminum single-layer reticulated shells","volume":"142","author":"Ma","year":"2019","journal-title":"Thin-Walled Struct."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1466","DOI":"10.1177\/1369433216682506","article-title":"Constant amplitude fatigue test research on M20 high-strength bolts in grid structure with bolt-sphere joints","volume":"20","author":"Yang","year":"2017","journal-title":"Adv. Struct. Eng."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"110590","DOI":"10.1016\/j.engstruct.2020.110590","article-title":"Effect of insufficient screwing depth of bolt on mechanical behavior of bolt-ball joint and stability of single-layer reticulated shell","volume":"213","author":"Wu","year":"2020","journal-title":"Eng. Struct."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1355","DOI":"10.1007\/s13296-020-00368-8","article-title":"Experimental investigation on tensile properties of the bolt in sphere joints Under Fire","volume":"20","author":"Huang","year":"2020","journal-title":"Int. J. Steel Struct."},{"key":"ref_13","first-page":"198","article-title":"Experimental study on mechanical properties of high strength bolts used in steel grid bolted spherical joints after fire","volume":"42","author":"Feng","year":"2021","journal-title":"J. Build. Struct."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Si, Q., Tang, Y., Zong, L., Liu, H., and Kang, B. (2022). Experimental Study and Numerical Simulation of the Tensile Properties of Corroded Bolt-Sphere Joints. Buildings, 12.","DOI":"10.3390\/buildings12111989"},{"key":"ref_15","unstructured":"(2011). Technical Specification for Space Grid Structure (Standard No. JGJ 7-2010)."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"107293","DOI":"10.1016\/j.jcsr.2022.107293","article-title":"A review of experimental and computational modelling of dynamic bolt fracture","volume":"194","author":"Warren","year":"2022","journal-title":"J. Constr. Steel Res."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1297","DOI":"10.1016\/j.proeng.2011.04.216","article-title":"Fatigue properties of high strength bolts","volume":"10","author":"Marcelo","year":"2011","journal-title":"Procedia Eng."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1520\/JAI13075","article-title":"Influence of cold rolling threads before or after heat treatment on the fatigue resistance of high strength coarse thread bolts for multiple preload conditions","volume":"3","author":"Stephens","year":"2005","journal-title":"J. ASTM Int"},{"key":"ref_19","first-page":"171","article-title":"Design and Optimization of Screwed Fasteners to Reduce Stress Concentration Factor","volume":"4","author":"Govindu","year":"2015","journal-title":"J. Appl. Mech. Eng."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1849","DOI":"10.1016\/j.proeng.2010.03.199","article-title":"Experimental determination of the fatigue life of modified threaded pipe couplings","volume":"2","author":"Wahab","year":"2010","journal-title":"Procedia Eng."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"12","DOI":"10.9790\/1684-0711219","article-title":"Experimental Evaluation of the Effect of Thread Angle on the Fatigue Life of Bolts","volume":"7","author":"Mushtaq","year":"2013","journal-title":"J. Mech. Civil Eng."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1016\/j.ijfatigue.2014.11.005","article-title":"Experimental characterization of the bending fatigue strength of threaded fasteners","volume":"72","author":"Wentzel","year":"2015","journal-title":"Int. J. Fatigue"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Kumar, S., Ramkumar, J., and Kyratsis, P. (2022). Recent Advances in Manufacturing Modelling and Optimization, Springer.","DOI":"10.1007\/978-981-16-9952-8"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"545","DOI":"10.1016\/0013-7944(94)00171-D","article-title":"Stress Intensity Factors for Threaded Connections","volume":"50","author":"Brennan","year":"1995","journal-title":"Int. J. Eng. Fract. Mech."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"419","DOI":"10.1016\/0045-7949(95)00277-4","article-title":"Stress Intensity Factor for a Semi-Elliptical Surface Crack at the Thread Root of a Screwed-Pipe Joint","volume":"59","author":"Zhao","year":"1996","journal-title":"Int. J. Comput. Struct."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"128","DOI":"10.1016\/j.ijfatigue.2006.01.017","article-title":"Stress Intensity Factors in a Hollow Cylinder Containing a Circumferential Semi-Elliptical Crack Subjected to Combined Loading","volume":"29","author":"Shahani","year":"2007","journal-title":"Int. J. Fatigue"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"021202","DOI":"10.1115\/1.4007290","article-title":"Effect of helix angle on the stress intensity factor of a cracked threaded bolt","volume":"135","author":"Kumar","year":"2013","journal-title":"J. Press. Vessel Technol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"244","DOI":"10.1007\/s40430-020-02326-1","article-title":"Analysis of fatigue crack growth in cylinder head bolts of gasoline engine based on experimental data","volume":"42","author":"Aliakbari","year":"2020","journal-title":"J. Braz. Soc. Mech. Sci. Eng."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Recho, N. (2012). Fracture Mechanics and Crack Growth, John Wiley & Sons, Ltd.","DOI":"10.1002\/9781118387184"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"897","DOI":"10.1016\/0013-7944(78)90043-7","article-title":"Stress intensity factors for a circumferential crack emanating from a notch in a round tensile bar","volume":"10","author":"Lefort","year":"1978","journal-title":"Eng. Frac. Mech."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"447","DOI":"10.1016\/0013-7944(84)90050-X","article-title":"Stress analysis of a strip with a step and a crack","volume":"20","author":"Hasebe","year":"1984","journal-title":"Eng. Fract. Mech."},{"key":"ref_32","unstructured":"(2020). ISO General Purpose Screw Threads, Basic Profile, Part 1: Metric Screw Threads (Standard No. ISO 68-1: 1998\/Amd 1: 2020)."},{"key":"ref_33","unstructured":"(2001). Metric Cable Glands for Electrical Installations (German Version) (Standard No. DIN EN 50262: 2002)."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s00419-012-0622-8","article-title":"Optimization of bolt thread stress concentrations","volume":"83","author":"Pedersen","year":"2013","journal-title":"Arch. Appl. Mech."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"216","DOI":"10.1520\/JTE11230J","article-title":"Stress intensity factors for single-edge-crack solid and hollow round bars loaded in tension","volume":"9","author":"Horstman","year":"1981","journal-title":"J. Test. Eval."},{"key":"ref_36","unstructured":"Toor, P.M. (1995). Improved Technology for Critical Bolting Applications, American Society for Testing & Materials."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/16\/10\/3781\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T19:36:45Z","timestamp":1760125005000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/16\/10\/3781"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,5,17]]},"references-count":36,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2023,5]]}},"alternative-id":["ma16103781"],"URL":"https:\/\/doi.org\/10.3390\/ma16103781","relation":{},"ISSN":["1996-1944"],"issn-type":[{"type":"electronic","value":"1996-1944"}],"subject":[],"published":{"date-parts":[[2023,5,17]]}}}