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Quantification of Clamp Loss and Subsequent Loosening of Automotive Hub-Knuckle Joints under Time-Varying Proving Ground Loading

FCA US LLC-Sandip Datta, Parag Nittur
  • Technical Paper
  • 2020-01-0181
To be published on 2020-04-14 by SAE International in United States
Threaded fasteners or bolted joints are used extensively in automotive assemblies. There are standard procedures to evaluate joint performance under block cycles or road loads. The deciding load case for such joint design is slippage analysis of the joint.There are studies done to evaluate the theoretical and experimental behavior of these joints. There are different ways of understanding the interaction between the bolt and the nut under different loading scenarios. However, none have provided a satisfactory method of quantifying bolt loosening or loss of clamp load under cyclic loading, where no slippage is observed.Under varying loads, initial relaxation of the joint is followed by a loss of clamping load. Below a critical value, complete loss of clamping load progresses very rapidly and this results in a loose joint. The loss of clamping load below the critical value happens at a transition stage when both elastic deformations of the bolt as well as external moments contribute to rapid loosening.This study provides an overall understanding of geometric parameters that contribute to sudden loss of clamping load and…
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Defect Detection of Railway Fasteners Based on Improved PHOG Characteristics

SAE International Journal of Transportation Safety

China-Jiaming Hu
Northeast Electric Power University, China-Chun-Ming Wu
  • Journal Article
  • 09-08-01-0002
Published 2020-03-23 by SAE International in United States
Aiming at the problem of low recognition rate and slow speed caused by the small proportion of key area information in feature vectors of original Pyramid Histogram of Gradients (PHOG) features, an improved feature extraction method of PHOG is proposed. The PHOG feature extraction method is combined with edge feature enhancement method based on Census transform to extract feature vectors of fasteners, and dimensionality reduction is processed by Kernel Principal Component Analysis (KPCA) method to reduce the interference of redundant information. The vector is inputted into the support vector machine for training in order to get the classifier model and realize the automatic identification of the fastener’s state. The simulation results show that compared with the traditional PHOG method, this feature extraction method improves the false detection rate by 2.7%, and the complexity of the algorithm is greatly reduced.
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Item Level Serialization and Traceability of Aerospace Fasteners Based on Individual Inherent Surface Patterns

Arconic Fastening Systems-Luke Leonard Haylock, Jens Harde, Jürgen Rösing, Nils Murray, Torsten Timpe
fraunhofer-Tobias Schmid-Schirling, Norbert Saum lng, Daniel Carl
  • Technical Paper
  • 2020-01-0012
Published 2020-03-10 by SAE International in United States
Item level serialization traceability, defined as the ability to track and trace products, items or components through the supply chain from product manufacturing all the way to the end of life service, has significant value in the aerospace industry. Many items become susceptible to counterfeiting when their origin and authenticity cannot be verified and Item level serialization and traceability fosters supply chain integrity. Data Matrix and radio-frequency identification (RFID) are two common methods that enable detailed information about the manufacturer. However, these methods are not generally compatible with fasteners due to the small size of the fasteners and the cost of these methods. Fasteners are the most commonly used parts on an aircraft and rely on lot level traceability associated with packaging to provide a level of supply chain risk management. However, the association of individual fasteners to parental lots is often lost once the fasteners are removed from packaging. We demonstrate a completely new approach to develop item level serialization traceability for aerospace fasteners. It is demonstrated that this label-free traceability can be realized…
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A Communication-Free Human-Robot-Collaboration Approach for Aircraft Riveting Process Using AI Probabilistic Planning

Saarland University-Jörg Hoffmann
ZeMA gGmbH-Khansa Rekik, Rainer Müller, Matthias Vette
  • Technical Paper
  • 2020-01-0013
Published 2020-03-10 by SAE International in United States
In large scale industries attempts are continuously being made to automate assembly processes to not only increase productivity but also alleviate non-ergonomic tasks. However this is not always technologically possible due to specific joining challenges and the high number of special-purpose parts. For the riveting process, for example, semi-automated approaches represent an alternative to optimizing aircraft assembly and to reduce the exposure of workers to non-ergonomic conditions entailed by performing repetitive tasks.In [1], a semi-automated solution is proposed for the riveting process of assembling the section barrel of the aft section to its pressure bulkhead. The method introduced a dynamic task sharing strategy between human and robot that implements interaction possibilities to establish a communication between a human and a robot in Human-Robot-collaboration fashion. Although intuitive, interacting with the robot constantly is still not natural for the worker as in the manual process no explicit communication between both workers is needed.In this work a communication-free Human-Robot-collaboration solution is presented. The method developed not only enables sharing assembly missions by dividing tasks based on skills, but…
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In-Process Hole and Fastener Inspection Using a High-Accuracy Laser Sensor

Electroimpact Inc.-Zachary Luker, Erin Stansbury
  • Technical Paper
  • 2020-01-0015
Published 2020-03-10 by SAE International in United States
Electroimpact has produced a new in-process inspection system for use on drilling and fastening systems. The system uses a high-accuracy, non-contact, laser system to measure the flushness of installed fasteners. The system is also capable of measuring part normality and providing feedback to the machine for correction. One drawback to many automatic inspection systems is measurement error. Many sources of measurement error exist in a production environment, including drilling chips, lubrication, and fastener head markings. Electroimpact’s latest system can create a visualization of the measured fastener for the operator to interpret. This allows the operator to determine the cause of a failed measurement, thus reducing machine downtime due to false negatives.Electroimpact created a custom C# WPF application that queries the point-cloud data and analyzes the raw data. A custom “circle Hough transform” scoring algorithm is used to find the center of the nosepiece (pressure foot). A best fit plane is calculated from the point cloud data to find the panel surface. This plane is then used to output panel normality in the A and B…
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Metallic Materials Properties Development and Standardization (MMPDS) Handbook - 14

  • Book
  • B-986
Published 2020-03-05 by Battelle Memorial Institute in United States

The Metallic Materials Properties Development and Standardization MMPDS-14supersedes MMPDS-13 and prior editions of the MMPDS Handbook as well as all editions of MIL-HDBK-5, Metallic Materials and Elements for Aerospace Vehicle Structures Handbook that was maintained by the U.S. Air Force. The last edition, MIL-HDBK-5J was cancelled by the U.S. Air Force in March 2006.

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Rivets, Carbon Steel Procurement Specification for

E-25 General Standards for Aerospace and Propulsion Systems
  • Aerospace Standard
  • AS7225B
  • Current
Published 2020-01-03 by SAE International in United States
This procurement specification covers aircraft-quality solid rivets and tubular end rivets made from a carbon steel of the type identified under the Unified Numbering System as UNS G10100.
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Influence of cutting fluid on reliability of threaded fastener joints

Atlas Copco Industrial Technique AB, Sickla Industrial 19, 1-Erik Persson
System and Component Design, Department of Machine Design, K-Mayank Kumar, Sergei Glavatskih
  • Technical Paper
  • 2019-01-2300
Published 2019-12-19 by SAE International in United States
This study reports on the effect of cutting fluids on friction behavior of the threaded fasteners. Underhead and thread friction are measured during tightening process of the hex-head threaded fasteners coated with different zinc-based coatings: electroplated zinc, zinc flake, and electroplated zinc nickel, commonly used in the automotive industry. The tests and data analysis are conducted considering ISO 16047 as a baseline. Test conditions are set close to the actual production conditions found in the motor vehicle industry. Water-based and ester-based cutting fluids are selected to unveil their impact on the reliability of the threaded fastener joints. It is shown that a change in the underhead interface conditions from dry to lubricated drastically reduces friction for the electroplated zinc and zinc nickel coatings.
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STUD, LOCKED IN, KEY LOCKED, UNS S66286, 140 KSI/1200 °F LIGHTWEIGHT, SELF-BROACHING KEYS

E-25 General Standards for Aerospace and Propulsion Systems
  • Aerospace Standard
  • AS3543B
  • Current
Published 2019-12-03 by SAE International in United States
No Abstract Available.
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STUD - STRAIGHT, NECKED, .3750-16UNS X .3750-24UNF-3A

E-25 General Standards for Aerospace and Propulsion Systems
  • Aerospace Standard
  • AS126881B
  • Current
Published 2019-11-21 by SAE International in United States
No Abstract Available.
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