Lemmen H.J.K.,Technical University of Delft |
Alderliesten R.C.,Technical University of Delft |
Pieters R.R.G.M.,Technical University of Delft |
Benedictus R.,Technical University of Delft |
Pineault J.A.,Proto Manufacturing Ltd
Journal of Aircraft | Year: 2010
Friction-stir welding is a relatively new joining technology that has great potential for the aerospace industry. To use friction-stir welding to manufacture an airworthy and damage-tolerant structure, the mechanical behavior must be fully understood. This paper presents the experimental results in which the local yield strength and the residual stress profile for friction-stir-welded AA2024-T3, AA7075-T6, and AA6013-T4 were measured. X-ray diffraction was used to measure the residual stresses. The residual stress profiles in all three alloys exhibited high tensile stresses in the center region of the weld. Around the weld the stress levels were reduced to either zero or low-magnitude compressive stresses. Both AA2024-T3 and AA7075-T6 show comparable residual stress profiles, whereas AA6013-T4 exhibits lower-magnitude residual stresses. Digital imaging correlation was used to measure the local yield strength in all three alloys with and without welds. The yield strength profiles obtained with this new technology matched perfectly with the corresponding hardness profiles of the welds. A relation was found between the yield strength profiles and the residual stress profiles, which resulted in understanding of how the appearance of the residual stress profiles is determined by the yield strength profile. April 2010. Copyright © 2010 by the American Institute.
Nantais J.,Proto Manufacturing Ltd |
Pineault J.,Proto Manufacturing Inc |
Belassel M.,Proto Manufacturing Inc |
Brauss M.,Proto Manufacturing Inc
SAE International Journal of Materials and Manufacturing | Year: 2013
Automobile manufacturers have experienced increasing consumer and regulatory pressure to improve fuel efficiency and crashworthiness while simultaneously decreasing overall vehicle body weight. As such, the use of advanced high strength steels (AHSS) in body panels and other structural elements is becoming more and more prevalent because these advanced materials present an economical and elegant solution to the problem. To ensure the quality and safety of AHSS components, residual stress (RS) specifications (among others) have been introduced with the intent to minimize failures experienced both in the field and during production. Moreover, when welding processes are applied to AHSS components, the localized loss of ductility in combination with tensile RS can result in localized cracking, distortion, and/or failures. Spot checks at critical locations (often selected using either modeling methods and by experience) are currently being performed however, the highest RS present in the component may be overlooked in some cases. To achieve a more thorough understanding of the range and distribution of potentially harmful RS in AHSS components, large areas can be characterized using RS mapping techniques. This paper will present several examples of RS maps collected on various geometries on AHSS automotive body panels and structural elements demonstrating the variation and range of RS present. © 2013 SAE International.
Proto Manufacturing Ltd. | Date: 2014-03-14
An x-ray diffraction apparatus is provided having an x-ray diffraction head, a frame for supporting the x-ray diffraction head, and a pair of drive mechanisms of the frame configured to generate pivotal movement of the x-ray diffraction head about first and second orthogonal axes. The frame is configured such that operation of one of the drive mechanisms to rotate the x-ray diffraction head about the first axis generates rotation of both of the drive mechanisms about the first axis.
Belassel M.,Proto Manufacturing Ltd |
Pineault J.,Proto Manufacturing Ltd |
Brauss M.,Proto Manufacturing Inc
SAE International Journal of Materials and Manufacturing | Year: 2012
Several residual stress (RS) measurement standards that employ x-ray diffraction (XRD) techniques are available for users in Europe, North America, Japan and other countries. Such standards are similar in principle however the detailed requirements for each standard are different. RS measurements performed on critical components require a good knowledge of XRD techniques and current best practices so that they can be correctly applied to the challenging geometries and exotic materials that often compose critical components of interest. This paper will compare the key requirements found in the various RS measurement guidelines and standards currently available to users while emphasizing and justifying current best practices as they apply to the measurement of RS on mechanical components used in the automotive and the aerospace industry. © 2012 SAE International.