Development of a Monitoring System for Crack Growth in Bonded Single-Lap Joints Based on the Strain Field and Visualization by Augmented Reality

Abstract

In this work, a method for monitoring fatigue crack growth in a metal to composite bonded joint based on the strain field is proposed and applied in the framework of a visualization tool based on Augmented Reality (AR). This tool superimposes some virtual objects, which are the data acquired by the sensors and the crack length, directly on top of the specimen under inspection and in real time. By finite element (FE) analyses, a good correlation between the crack tip position and the strain field in a single lap specimen is found and this feature is exploited to monitor the crack length during fatigue tests and to feed the AR system to virtually visualize the crack on the real specimen. An array of electrical resistance strain gauges is bonded to the surface of one adherend. A Matlab function collects values from the strain gauges mounted on the specimen under investigation analyses them on the basis of the FE analysis and finally feeds the AR system. The validation of this process is done by measuring the crack by optical microscope. This procedure is also tested with the use of Fiber Bragg Gratings (FBG) optical strain gauges

Evaluation of mode II fatigue disbonding using Central Cut Plies specimen and distributed strain sensing technology

“…[40][41][42][43][44] Among several possibilities, an interesting approach uses back-face strain measurements and correlates them to the damage evolution. [45,46] This method presented some improvements with the use of fiber optics and distributed strain sensing technology [47][48][49][50][51] and it seems to give valuable information about damage evolution on bonded joints. For this work, the compliance method using a clip extensometer was used to calculate the disbond growth rate of CCP specimens along with a backface strain measurement technique using optical fibers.…”

Improved human-computer interaction for mechanical systems design through augmented strain/stress visualisation

“…In [24,25], an AR framework for inspection and visualization during fatigue tests was successfully adopted. By sharing the same advantages deriving from the use of AR as the HCI, this paper proposes an efficient scheme for simulating the deformation of structural components in real-time, thus enabling the inclusion of the structural behavior in the virtual prototyping experience, for the ultimate purpose of design validation.…”

A State-of-the-Art Review of Augmented Reality in Engineering Analysis and Simulation

“…Clothier et al [63] Assist on-site operation Underkoffler et al [64] Malkawi et al [65,66] Intuitive analysis environment Carmo et al [33,34] Heuveline et al [35,36] Golparvar-Fard et al [67,68] Graf et al [69] Intuitive design environment Broll et al [37] Fukuda et al [38,39] Mechanical engineering & Manufacturing Weidlich et al [70] Intuitive analysis environment NUS AR group, [27,41,42] Paulus, et al [43] Uva et al [44,45,47,48] Issartel et al [71] Bernasconi et al [40] Valentini et al [49,50] Naets et al [72] Moreland et al [73] Regenbrecht et al [74] Intuitive design environment Niebling et al [46] Weidenhausen et al [75] Electromagnetism Buchau et al [76] Training and education Ibáñez et al [51] Silva et al [77] Intuitive analysis environment Mannuß et al [52] Matsutomo et al [53,54] Table 6 summarizes the features and limitations of most of the AR-based engineering analysis and simulation systems. Selected studies use different visualization methods, such as image overlay, OpenGL programming, and special software kit, to visualize volumetric data and numerical simulation results.…”

“…Outdoor AR systems could serve as a tool to assist in important decisions without constraining the user's whereabouts to a specially equipped area. Some of the selected studies are based on a client-server network model for visualization of simulation data [33][34][35][36][38][39][40]45,47,48,55,60,69,75]. However, due to limited device capabilities, mobile AR platforms still require further development for engineering analysis and simulation.…”

“…With AR, civil engineers and urban designers can examine simulated results in the outdoor environment [33][34][35][36] and improve design in the indoor environment [37][38][39]. In the mechanical engineering and manufacturing fields, near real-time result updating with sensor networks [27,[40][41][42], image processing [43], and tangible user interfaces [44][45][46][47][48][49][50] (Table 4) are common practices. As can be seen in Tables 2 and 3, most of the selected studies in these two fields are based on a specific visualization tool instead of image overlay.…”