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The article offers information on of use of large shearbox, a rapid test used for measurement of the shear strength of soils. It presents information on drained strength and residual strength shearbox tests. It mentions that material is compacted into shearbox already in place in the machine, if possible, to avoid the difficulties of subsequent handling.

Despite the success of surgical implants such as artificial hip, materials used in these procedures still do not satisfy the demands of human life time functioning. Currently used materials such as titanium alloys, ceramics and polymers are degraded after about a dozen years of use. Diamond coating technology has proven to be efficient in the performance of human joints. In this study, we have investigated the deposition of diamond thin films on Ti6Al4V using a new developed time-modulated Chemical Vapour Deposition (TMCVD) method. Finite element simulations were used to analyse the development of residual stresses. Micro Raman spectroscopy was also used to evaluate the residual stresses and compare with numerical models. [ABSTRACT FROM AUTHOR]

The densification behavior along with the microstructure evolution and some mechanical properties of four ultrafine SiC particle-dispersed ZrB2 matrix composites were studied. The SiC–ZrB2 composites, with a SiC content of 5, 10, 15 and 20 vol%, were densified to near full density by vacuum hot pressing at 1,900°C under a maximum uniaxial pressure of 45 MPa. The presence of SiC greatly improved the sinterability of ZrB2. Grain growth of the diboride matrix was increasingly inhibited for larger amounts of SiC added. Elastic modulus, Poisson ratio, microhardness, flexural strength and fracture toughness were measured at room temperature. Unexpectedly, no obvious effect of the increasing amount of SiC on flexural strength and fracture toughness was found. The former property ranged from 650 to 715 MPa but was actually affected by the exaggerated size of several tenths of micrometers of sintered SiC clusters which acted as dominant critical defects. Also fracture toughness did not receive a marked contribution from the increase of the SiC content. As for the matrix, the prevailing fracture mode of the composites was intragranular, regardless of the SiC content. [ABSTRACT FROM AUTHOR]

Pulsed neutron beams available at the ISIS spallation source offer diverse possibilities for materials characterization using diffraction and imaging. In this paper we review a range of applications of the time-of-flight neutron diffraction for the characterization of phase transformations and residual stress states in industrially-relevant situations. The setup of the ENGIN-X instrument at ISIS is described, followed by a series of case studies based on the recently obtained results. [ABSTRACT FROM AUTHOR]

The effect of autofrettage on thick-walled cylinders, operating under high internal pressure, has become a significant area of development, both in research and practice. In optimal design of thick-walled cylinders, there are two main objectives to be achieved: increasing its strength-weight ratio and extending its fatigue life. This can be achieved by generating a residual stress field in the cylinder wall prior to use. Both analytical and numerical techniques have been used for the investigation of the effects of residual stresses on the load-carrying capacity. The scope of the current paper includes application of ABAQUS finite element code to the direct problem of finding thick-walled cylinder autofrettage solutions. The results reveal three scenarios in the design of thick-walled cylinders. For maximum load carrying capacity, non-autofrettage is suitable when, in service, the whole wall thickness will be yielded. Full autofrettage is suitable when, during subsequent operation, yielding is limited at the inner surface. Optimum autofrettage of the cylinder is suitable if a minimum equivalent stress is to be achieved. The analytical solutions were compared to numerical results and a very good correlation in form and magnitude was obtained. [ABSTRACT FROM AUTHOR]

The HCF response to burnishing of a number of structural materials is compared and contrasted. It is shown that alloys which exhibit marked work-hardening during burnishing respond very beneficially with regard to HCF performance while others which show little work-hardening may even react with losses in HCF strength. Possible explanations for such behavior are outlined in terms of mean stress and environmental sensitivities of the fatigue strengths of the various materials and microstructures. [ABSTRACT FROM AUTHOR]

Welding joining processes such as, laser-beam, friction-stir and arc welding lead to the development of residual stresses. Cracks developed at the influenced regions grow under the effect of these residual stresses and additional attention is required to be paid to the assessment of the structural integrity. In the present work three-dimensional Finite Element Analysis is utilized for the calculation of Stress Intensity Factors at cracks in welded components. The developed residual stress fields are calculated from the numerical simulation of the thermo-mechanical process. The fracture analysis methodology is initially validated by comparison of numerical results with existing analytical solutions for the case of a flat plate under typical welding residual stresses. Finally, the numerical procedure is applied to the study of the effect of residual stress fields on SIF values at cracks in welded stiffened panels. [ABSTRACT FROM AUTHOR]

The work presents extensive experimental data proclaiming the potential enhancement on the fatigue life of integral structures using the Esonix Ultrasonic Impact Treatment. [ABSTRACT FROM AUTHOR]

In order to predict the durability of engineering components and improve performance, it is mandatory to understand residual stresses. The last decade has witnessed a significant increase of residual stress evaluation using diffraction of penetrating radiation, such as neutrons or high energy X-rays. They provide a powerful non-destructive method for determining the level of residual stresses in engineering components through precise characterisation of interplanar crystal lattice spacing. The unique non-destructive nature of these measurement techniques is particularly beneficial in the context of engineering design, since it allows the evaluation of a variety of structural and deformational parameters inside real components without material removal, or at worst with minimal interference. However, while most real engineering components have complex shape and are often large in size, leading to measurement and interpretation difficulties, since experimental facilities usually have limited space for mounting the sample, limited sample travel range, limited loading capacity of the sample positioning system, etc. Consequently, samples often have to be sectioned, requiring appropriate corrections on measured data; or facilities must be improved. Our research group has contributed to the development of engineering applications of high-energy X-ray diffraction methods for residual stress evaluation, both at synchrotron sources and in the lab setting, including multiple detector setup, large engineering component manipulation and measurement at the UK Synchrotron Radiation Source (SRS Daresbury), and in our lab at Oxford. A nickel base superally combustion casing and a large MIG welded Al alloy plate were successfully studied. [ABSTRACT FROM AUTHOR]

The aim of this investigation was to ascertain the changes in residual stress profile after the post-treatment of functionally graded thermal spray WC-NiCrBSi coatings, and relate these changes to the microstructural transformations. Through thickness residual stress measurements were performed using the neutron diffraction and x-ray diffraction techniques. Functionally graded HVOF (JP5000) WC-NiCrBSi coatings were thermally sprayed on AISI 440C steel substrate discs. These coatings were then heat-treated in an inert atmosphere at 1200°C for one hour. Microstructural investigations using SEM, XRD, and light microscopy were used to identify the changes after the heat-treatment. Microhardness and indentation modulus values were also investigated to analyse the changes in the mechanical properties after the heat-treatment. Results of this investigation indicated that the residual stress gradient within the coating material decreases after the heat-treatment, and the stress field in the substrate, near the coating substrate interface, changes from tensile to compressive. Residual stress measurements via x-ray diffraction provided average compressive values which were similar to those evaluated via the neutron diffraction technique, however the definition of stress gradient as a function of coating thickness was much better resolved via the neutron diffraction technique. The changes in the stress gradient after the heat-treatment were related to the microstructural changes which resulted in the formation of diffusion zones at the coating substrate interface, and also at the interface of functionally graded coating, improvement in coating elasticity due to the changes in the bonding mechanism from mechanical interlock to metallurgical bonding, and the formation of secondary phases within the coating microstructure. [ABSTRACT FROM AUTHOR]

To be able to accurately design structures and make reliability predictions, in any field it is necessary first to know the mechanical properties of the materials that make up the structural components. In the fields of microelectromechanical systems (MEMS) MEMSand nanoelectromechanical systems (NEMS), nanoelectromechanical systemsthe devices are necessarily very small. The processing techniques and microstructures of the materials in these devices may differ significantly from bulk structures. Also, the surface-area-to-volume ratio in these structures is much higher than in bulk samples, and so the surface properties become much more important. In short, it cannot be assumed that mechanical properties measured using bulk specimens will apply to the same materials when used in MEMS and NEMS. This chapter will review the techniques that have been used to determine the mechanical properties of micromachined structures, especially residual stress, strength, and Young’s modulus. The experimental measurements that have beenperformed will then be summarized, in particular the values obtained for polycrystalline silicon (polysilicon). [ABSTRACT FROM AUTHOR]

Chapter 11 of the book "Pipe Welding Procedures" is presented. The chapter offers an introduction to welding metallurgy. Topics discussed include metal properties, grain structure of metals, structural characteristics of steel, alloying elements in steel and stress relieving in metals. Also discussed is the structure of the weld as well as residual stresses and distortion in welds.

Chapter 5 covers residual stresses, distortion, and fatigue of welds, including: Residual Stresses (development of residual stresses; calculation of residual stresses; stress relief by postweld heat treatment); Distortion (cause; remedies: reducing weld metal volume, welding alternately on either side of double-V joint, placing weld around neutral axis, presetting, prespringing and preheating); Fatigue (mechanism; fractography; S–N curves; effect of joint geometry, stress raisers and corrosion; remedies: shot pinning and reducing stress raisers); Case Studies; 24 Illustrations, 22 References, and 3 Exercise Problems [ABSTRACT FROM PUBLISHER]

This article focuses on magnetic methods of nondestructive evaluation. Magnetic methods of nondestructive evaluation are used to find three major types of information: detection and characterization of macroscopic flaws in a specimen such as cracks, corrosion pits, or inclusions; characterization of microstructural features such as creep damage, plastic deformation, grain size, and compositional features and characterization of residual stress and residual stress distribution in a specimen. Magnetic particle inspection (MPI) was developed in the 1930s by Magnaflux Corp. MPI depends on the leakage of magnetic flux at the surface of a ferromagnetic material at locations of surface-breaking or near-surface.

The article offers information on several terms used in measurement of the shear strength of soils. It presents definitions of shear force, undrained shear strength, Apparent cohesion, Free-draining soil, Residual strength, Torsion, Torque, and Vane shear strength. It states that soil in which water can move easily through the void spaces so that no excess pore pressure or suction develops as a result of the application of stress or deformation.

Pulsed neutron beams available at the ISIS spallation source offer diverse possibilities for materials characterization using diffraction and imaging. In this paper we review a range of applications of the time-of-flight neutron diffraction for the characterization of phase transformations and residual stress states in industrially-relevant situations. The setup of the ENGIN-X instrument at ISIS is described, followed by a series of case studies based on the recently obtained results. [ABSTRACT FROM AUTHOR]