Identification of damage stages in bolted metallic joints for different joint geometries and tightening torques using statistical analysis

Abstract

The main parameters controlling the structural behavior of bolted joints are the tightening torque ( T) and the joint geometry such as the edge distance ( e) to the bolt hole diameter ( D) ratio ( e/ D) and the joint width ( W) to the hole diameter ratio ( W/ D). In the first part of this study, the effects of W/ D and T, with a constant value of e/ D ( e/ D = 3), have been studied experimentally. Three values of W/ D (2.25, 3, and 3.75) with six values of T (0, 10, 15, 20, 25, and 30 N m) have been chosen to construct 18 assemblies. Experimental results highlighted the impact of W/ D, and T, on the different failure stages of bolted double-lap metallic joints. In the second part of this study, analysis of variance has been adopted to analyze the effects of T and W/ D in addition to the effect of e/ D which has been studied previously by the authors. The present experimental results showed that the value of applied load at which the sticking failure occurred increased by increasing the tightening torque up to T = 25 N m for all values of W/ D. However, the other stages of failure were slightly affected by the value of T. The results obtained from the analysis of variance identified that there is no clear effect of W/ D and e/ D on the sticking failure load. However, their effects are markedly clear for other stages of failure.

Combined Joint and Member Damage Identification of Semi-Rigid Frames with Slender Beams Considering Shear Deformation

“…The Timoshenko beam theory was proposed by Timoshenko in 1921 [40,41]. Timoshenko beam theory provides shear deformation and rotatory inertia corrections to the clas-sical Euler-Bernoulli beam theory, so the member stiffness matrix is more complex [42][43][44], as shown in Equation (2).…”

“…In general, the analysis and design of frame structures should fully grasp the mechanical behavior of their connections since the joint stiffness have a significant influence on the static behavior and dynamic behavior of the entire structure [1][2][3]. The conventional approaches to the analysis and design of frame structures assume that beam-to-column connections as either totally rigid or pinned.…”

Degradation and failure analysis of bolted joints under transverse loading

“…There are different failure modes and performance requirements for shear bolted joints in various engineering applications [25][26]. Abd-Elhady et al [27] investigated the effect of structural dimensions and tightening torque on the failure stage of bolted joints. Khashaba et al [28] found that the slope of the force-displacement curve was negatively related to the size of the washer under the same tightening torque.…”

Structural damage detection of space frame structures with semi-rigid connections

“…For frame structures, the connection joints have a significant influence on the dynamic behavior and integrity of the entire structure [22][23][24][25]. Compared with other members in the structure, the joints, e.g., welds or bolts, are more vulnerable to damage and critical for the overall safety.…”