X-ray stress measurement is widely used as one of the most powerful nondestructive tools to measure residual stresses in polycrystalline solids. In most cases, the sin2Ψ method has been used to determine the stress. In recent years, however, the cosα method has attracted engineers as a new method to measure the stress using two-dimensional detectors, such as imaging plates. The present article is the review of the state of the art of the cosα method. For biaxial stress cases, the cosα method utilizes the whole Debye-Scherrer ring recorded on a two-dimensional detector taken by single exposure of X-rays, and normal and shear stresses are determined simultaneously. The accuracy of the stress measurement of the cosα method has been confirmed to be equivalent to that of the sin2Ψ method for various metals. The simple optical system of the cosα method makes stress analyzers smaller, lighter and more convenient to use for on-site or field measurements. A recent portable stress analyzer adopting the cosα method shortens the measurement time to 60 s. The method has been further developed to analyze triaxial residual stresses. Various advantages of the cosα method are highlighted in comparison with the other methods of X-ray stress determination. Applications of the cosα method to machines and engineering structures are presented, together with future perspectives of the method.
Customizing offerings to match customers’ specific needs is a common practice for manufacturers striving to maintain their competence in markets. Despite Product/Service Systems (PSSs) having developed substantially in industry and academia for the last two decades, no scientific review of PSS customization has been published. This prompted us to conduct a review of scientific papers relating to products, services, and PSS customization with a focus on design, with the aim of clarifying future research directions in PSS customization. In particular, distinct design models and methods were individually examined, with a special focus on service aspects, in terms of what to design and how to design it. The population of papers included in the review was those included in the Web of Science. Even though service customization has been utilizing the knowledge generated by product customization, which has been researched extensively for decades, there are differences between them, such as the difficulty associated with modularity. The same or even larger differences apply to PSS customization, because, apart from service characteristics, PSS also has product characteristics and thus is more complex. Results also include that the module-based platform strategy used in service customization can also be used for PSS. Although several papers concerned with PSS customization have been published thus far, their focus has been on the service aspect of PSS, providing further research opportunities. Existing methods to design PSS can be also applied to develop a method for PSS customization.