Fatigue Property of Open-Hole Steel Plates Influenced by Bolted Clamp-up and Hole Fabrication Methods

Abstract

Steel plates with open holes are commonly used in structural assemblies. The fatigue properties of such details are influenced by bolted clamp-up and hole fabrication methods. The fracture surface, stiffness degradation and fatigue life of test specimens are investigated in detail and compared with the contemporary test data. The analysis results show that the presence of draglines greatly influences the fatigue crack initiation at the open-hole cut by laser. The bolted clamp-up condition greatly enhances the stiffness and the fatigue life of the open-hole details. A discussion is also made from a comparison with the referred fatigue life of hole fabrication details, such as the influence of plate thickness and plasma cutting, drilling and oxy-fuel gas cutting, with the details studied herein. This work could enhance the understanding of the fatigue property and design of such details.

Formation of a conductive network in urea−formaldehyde/carbon nanotube composite foams for electromagnetic shielding

“…Thermo‐expandable microspheres (EMs) are composed of thermoplastic polymer shells and liquid alkanes encapsulated in them 34 . Generally, the diameter of EMs is 10–30 μm, and the thickness of the polymer shell is 2–15 μm 35 . Due to the excellent elasticity of the polymer shell, when the microsphere is heated, with the gasification and expansion of internal alkanes, the volume of the microsphere increases several times without damage to the core−shell structure 36 .…”

“…34 Generally, the diameter of EMs is 10-30 μm, and the thickness of the polymer shell is 2-15 μm. 35 Due to the excellent elasticity of the polymer shell, when the microsphere is heated, with the gasification and expansion of internal alkanes, the volume of the microsphere increases several times without damage to the core−shell structure. 36 Therefore, such EMs can be used as a physical foaming agent to prepare foam materials with perfect closed cell structure.…”

Fatigue life prediction of steel bridge connections using fracture mechanics models

“…It has been found that crack growth in the open-hole specimens initiated almost exclusively at the edge of the hole. Thru thickness crack development around the edge of the hole appeared to be unsymmetrical in most cases [11]. The fatigue life of riveted sheet metal joints consisting of single as well as specimens with multiple fasteners was investigated.…”

Experimental Study on Fatigue Behaviour of Shot-Peened Open-Hole Steel Plates

“…Recently, the authors have also conducted a series of fatigue experimental research and comprehensive review of research work can be referred to [ 1 , 2 , 24 ]. For the improvement of fatigue strength, some other techniques, such as bolt clamp-up and carbon fibre-reinforced polymer (CFRP) strengthening, have also been recently highlighted by the authors [ 24 ] and other researchers. In [ 24 ], the combination of bolt clamp-up action was considered in the improvement of fatigue strength.…”

“…For the improvement of fatigue strength, some other techniques, such as bolt clamp-up and carbon fibre-reinforced polymer (CFRP) strengthening, have also been recently highlighted by the authors [ 24 ] and other researchers. In [ 24 ], the combination of bolt clamp-up action was considered in the improvement of fatigue strength. For the test specimen with centre hole covered with CFRP as reported in [ 25 ], it was shown an increased fatigue life of 54% over the un-retrofitted ones, while that only applied on either side of the crack starter exhibited only 25% life enhancement.…”