Engineering Applications of Residual Stress

Ultrasonic Technique and Equipment for Residual Stresses Measurement Part 1

ABSTRACT Different methods exist to measure the residual stresses (RS). One of the advantages of ultrasonic techniques for RS measurement is that they are non-destructive. Using such techniques, one can measure the RS in the same points many times, studying, for instance, the changes of RS under the action of service loading or effectiveness of […]

Ultrasonic Technique and Equipment for Residual Stresses Measurement Part 2

Compound Pipes and Pipes with Surfacing Another example of measuring the residual stresses by ultrasonic method is associated with compound pipes. Compound pipes are used in various applications and they are made by fitting under pressure one pipe with an outer diameter into a pipe with approximately the same inner diameter. For residual stress measurement, […]

Benchmark measurement of residual stresses in a 7449 aluminium alloy using deep-hole and incremental centre-hole drilling methods

ABSTRACT Residual stress measurements using non-destructive techniques including neutron diffraction and X-ray diffraction are dependent on assumptions made in the analysis. For example, the different stress free reference sample and the presence of precipitates in a material can influence the measured results. Previous residual stress measurement using neutron diffraction technique in a quenched aluminium block […]

A New Procedure for Measuring Residual Stresses in Electron Beam Welds Using the Deep Hole Drilling Technique

ABSTRACT Residual stress measurements in a thick cylindrical steel electron beam (EB) welded sample are described. This is a particularly challenging problem because the residual stresses are distributed in a very narrow region, in and adjacent to the EB weld, when compared to more conventional welding methods. Several variations of the deep hole drilling (DHD) […]

The Incremental Core Drilling Method to Determine In-Situ Stresses in Concrete

ABSTRACT The incremental core-drilling method (ICDM) is a nondestructive technique to assess in-situ stresses in concrete. In contrast to other available methods of in-situ stress measurement in concrete, the ICDM can quantify stresses that vary through the thickness of the concrete member under investigation, such as those due to bending or eccentric prestressing. In this […]

Influence of Drilling Parameters on the Accuracy of Hole-drilling Residual Stress Measurements Part 1

Abstract The objective of this research is to define drill speeds that produce acceptable results when using the hole-drilling technique for measuring residual stress. For this study, three common engineering materials; alloy 6061-T651 aluminum, 304 stainless steel, and A36 carbon steel were used. This was achieved by performing ESPI/hole-drilling stress measurement of a known applied […]

Influence of Drilling Parameters on the Accuracy of Hole-drilling Residual Stress Measurements Part 2

Results and Discussion As-Received Stress Measurements The aluminum exhibited a near-zero and near-uniform as-received surface stress throughout each of the twelve specimens. This is a very good result and exactly what we were looking for in specimen quality. Assuming that the stress distribution is relatively uniform across the longitudinal dimension, we will be able to […]

Residual Stress on Ti6Al4V Hybrid and Laser Welded Joints Part 1

ABSTRACT Ti6Al4V alloy combines mechanical strength, deformability, excellent fatigue and corrosion resistance and high strength to weight ratio. Furthermore, the mechanical behavior remains excellent at high temperature. Such characteristics make this material attractive for numerous applications (structural, aerospace and naval) because of recent improvements in welding techniques (laser, hybrid laser/MIG) that allow realizing high quality […]

Residual Stress on Ti6Al4V Hybrid and Laser Welded Joints Part 2

EXPERIMENTAL RESULTS Figures 5 and 6 show calculated residual stress in the transversal directions with respect to the weld cord. Stresses are plotted against the hole depth h. Plotted residual stresses are calculated by power series method. Some "strange" values have been measured at the first drilling steps probably produced during the surface preparation for […]

Residual Stresses Management: Measurements, Fatigue Analysis and Beneficial Redistribution Part 1

Abstract Residual stresses (RS) can significantly affect engineering properties of materials and structural components, notably fatigue life, distortion, dimensional stability, corrosion resistance. RS play an exceptionally significant role in fatigue of welded elements. The influence of RS on the multi-cycle fatigue life of butt and fillet welds can be compared with the effects of stress […]