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Bolt Hole
The Experts below are selected from a list of 3024 Experts worldwide ranked by ideXlab platform
M A Mccarthy – 1st expert on this subject based on the ideXlab platform
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stress analysis of single Bolt single lap countersunk composite joints with variable Bolt Hole clearance
Composite Structures, 2012Co-Authors: Brian Egan, M A Mccarthy, C T Mccarthy, R M FrizzellAbstract:Abstract Single-lap, carbon–epoxy joints with countersunk fasteners were modelled using the nonlinear finite element code Abaqus. A highly-detailed analysis of the stress distribution at the countersunk Hole boundary is provided. Bolt–Hole clearance, which arises due to limitations in manufacturing capabilities, is modelled extensively. Clearance levels both inside and outside typical aerospace fitting tolerances are studied and the finite element model is validated with experimental data. Plots of radial stress in each ply of the countersunk laminate show the load transfer to be severely localised, with only a few plies bearing the majority of the load. The inclusion of clearance in the model was shown to result in far higher radial stresses compared to those in the neat-fit joint model. An associated loss in joint stiffness of more than 10% was recorded for the highest clearance considered (240 μm). Finally compressive through-thickness stresses are shown to be present at the damageable region of the countersunk Hole, and increase with Bolt–Hole clearance. These compressive stresses, which are an indicator of lateral constraint, are seen to suppress “brooming” failure in the countersunk laminate.
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a simple method for determining the effects of Bolt Hole clearance on load distribution in single column multi Bolt composite joints
Composite Structures, 2006Co-Authors: M A Mccarthy, C T Mccarthy, G S PadhiAbstract:Abstract In this paper, a simplified method for determining the effects of Bolt–Hole clearance on the load distribution in composite multi-Bolt joints is presented. The method is applicable to joints with a single column of Bolts and is an extension of a previous method which did not include clearance effects. It can be applied to both single-lap and double-lap joints. The method is validated against three-dimensional finite element models, and some examples of different clearance cases are shown. It is shown that even small amounts of clearance can significantly alter the load distribution in the joint. Finally the method is used in a parameter study to examine the effects of various joint parameters on load distribution.
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three dimensional finite element analysis of single Bolt single lap composite Bolted joints part ii effects of Bolt Hole clearance
Composite Structures, 2005Co-Authors: C T Mccarthy, M A MccarthyAbstract:Abstract Three-dimensional finite element models have been developed to study the effects of Bolt–Hole clearance on the mechanical behaviour of Bolted composite (graphite/epoxy) joints. In Part I of this two-part paper, the model was developed in the finite element code MSC.Marc and validated against experiments and other finite element solutions. In this second part of the paper, results from the model showing the effects of clearance in single-lap, single-Bolt joints are presented and compared with experimental results. Both quasi-isotropic and zero-dominated lay-ups are studied. It is shown that increased clearance leads to increased Bolt rotation, decreased Bolt–Hole contact area, and decreased joint stiffness. In single-lap joints, clearance is shown to cause three-dimensional variations in the stress distribution in the laminate, and these variations are also dependent on the lay-up; the radial and tangential stresses in each ply are shown to illustrate this point. Finally, a prediction of the failure onset load using Hashin’s failure criteria is given and the results are compared with experimental results.
C T Mccarthy – 2nd expert on this subject based on the ideXlab platform
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stress analysis of single Bolt single lap countersunk composite joints with variable Bolt Hole clearance
Composite Structures, 2012Co-Authors: Brian Egan, M A Mccarthy, C T Mccarthy, R M FrizzellAbstract:Abstract Single-lap, carbon–epoxy joints with countersunk fasteners were modelled using the nonlinear finite element code Abaqus. A highly-detailed analysis of the stress distribution at the countersunk Hole boundary is provided. Bolt–Hole clearance, which arises due to limitations in manufacturing capabilities, is modelled extensively. Clearance levels both inside and outside typical aerospace fitting tolerances are studied and the finite element model is validated with experimental data. Plots of radial stress in each ply of the countersunk laminate show the load transfer to be severely localised, with only a few plies bearing the majority of the load. The inclusion of clearance in the model was shown to result in far higher radial stresses compared to those in the neat-fit joint model. An associated loss in joint stiffness of more than 10% was recorded for the highest clearance considered (240 μm). Finally compressive through-thickness stresses are shown to be present at the damageable region of the countersunk Hole, and increase with Bolt–Hole clearance. These compressive stresses, which are an indicator of lateral constraint, are seen to suppress “brooming” failure in the countersunk laminate.
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a simple method for determining the effects of Bolt Hole clearance on load distribution in single column multi Bolt composite joints
Composite Structures, 2006Co-Authors: M A Mccarthy, C T Mccarthy, G S PadhiAbstract:Abstract In this paper, a simplified method for determining the effects of Bolt–Hole clearance on the load distribution in composite multi-Bolt joints is presented. The method is applicable to joints with a single column of Bolts and is an extension of a previous method which did not include clearance effects. It can be applied to both single-lap and double-lap joints. The method is validated against three-dimensional finite element models, and some examples of different clearance cases are shown. It is shown that even small amounts of clearance can significantly alter the load distribution in the joint. Finally the method is used in a parameter study to examine the effects of various joint parameters on load distribution.
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three dimensional finite element analysis of single Bolt single lap composite Bolted joints part ii effects of Bolt Hole clearance
Composite Structures, 2005Co-Authors: C T Mccarthy, M A MccarthyAbstract:Abstract Three-dimensional finite element models have been developed to study the effects of Bolt–Hole clearance on the mechanical behaviour of Bolted composite (graphite/epoxy) joints. In Part I of this two-part paper, the model was developed in the finite element code MSC.Marc and validated against experiments and other finite element solutions. In this second part of the paper, results from the model showing the effects of clearance in single-lap, single-Bolt joints are presented and compared with experimental results. Both quasi-isotropic and zero-dominated lay-ups are studied. It is shown that increased clearance leads to increased Bolt rotation, decreased Bolt–Hole contact area, and decreased joint stiffness. In single-lap joints, clearance is shown to cause three-dimensional variations in the stress distribution in the laminate, and these variations are also dependent on the lay-up; the radial and tangential stresses in each ply are shown to illustrate this point. Finally, a prediction of the failure onset load using Hashin’s failure criteria is given and the results are compared with experimental results.
Jung-min Park – 3rd expert on this subject based on the ideXlab platform
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Bolting Cabin Assistance System Using a Sensor Network
International Journal of Advanced Robotic Systems, 2012Co-Authors: Yung Hak Mo, Yungeun Choe, Jung-min ParkAbstract:The Bolting cabin assistance system prevents operators from facing dangerous situations. This system consists of a Bolting robot control system and a top view supervisory system. In order to control the Bolting robot, circular Hough transforms and fuzzy reasoning are used. First, the circular Hough transform roughly estimates the location of the Bolt Hole. After that, errors of estimation are compensated for using fuzzy reasoning. In order to track a Bolt Hole, a region of interest (ROI) is used. By setting the region in which to search for a Bolt Hole, the algorithm tracks the location of the Bolt Hole. In order to choose an ROI, a template-based matching algorithm is used. In order to make the top view supervisory system, four cameras are installed at the left, right, front and back of the robot. The four individual images from the various cameras are combined to make the top view image after correcting for distortion.
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Cognition system of Bolt Hole using template matching
28th International Symposium on Automation and Robotics in Construction (ISARC 2011), 2011Co-Authors: Gwan Ryong Baek, Yung Hak Mo, Jae Sik Jeong, Jung-min ParkAbstract:In the construction field, the Bolting robot provides convenience and reduces a process time of assembling steel frames. When assembling steel frames, the Bolting robot finds a Bolt Hole with the help of camera. If the light conditions are either too bright or too dark, however, it is hard to find a Bolt Hole in the input image because the contrast between Bolt Hole and background is vague. In order to improve detection accuracy in such environment, this paper proposes the image processing algorithm using template matching (TM). First, the input image is converted from RGB to YCbCr in order to reduce influence of shadow. Then we separate Y channel of image in darkness or extract edges from Cb and Cr channel of image in brightness. Template image is created with the radius which can be calculated with the distance to a steel frame. We used TM to create the normalized cross correlation (NCC) image which shows correlation between processed image and template. Finally, Bolt Holes are extracted from the high-correlation part of NCC image. Experimental results show that the proposed method is robust to detect Bolt Holes under various illumination conditions.
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Robust detection system of a Bolt Hole using template matching and feature based matching
2011 11th International Conference on Control Automation and Systems, 2011Co-Authors: Yung Hak Mo, Jung-min ParkAbstract:This paper suggest a method to detect the Bolt Hole of the steel frame using the new detection that is combined template matching and the circular Hough transform. The template matching can be used to roughly estimate the location of the object under the various illumination. The circular Hough transform is used to discover more accurate location of the object than the template matching. Therefore, we compare the performance between each individual method and the mixed methods. We confirm that the proposed method is robust with respect to illumination.