X-ray computed tomography (CT) can reveal the internal details of objects in three dimensions non-destructively. In this Primer, we outline the basic principles of CT and describe the ways in which a CT scan can be acquired using X-ray tubes and synchrotron sources, including the different possible contrast modes that can be exploited. We explain the process of computationally reconstructing three-dimensional (3D) images from 2D radiographs and how to segment the 3D images for subsequent visualization and quantification. Whereas CT is widely used in medical and heavy industrial contexts at relatively low resolutions, here we focus on the application of higher resolution X-ray CT across science and engineering. We consider the application of X-ray CT to study subjects across the materials, metrology and manufacturing, engineering, food, biological, geological and palaeontological sciences. We examine how CT can be used to follow the structural evolution of materials in three dimensions in real time or in a time-lapse manner, for example to follow materials manufacturing or the in-service behaviour and degradation of manufactured components. Finally, we consider the potential for radiation damage and common sources of imaging artefacts, discuss reproducibility issues and consider future advances and opportunities. This Primer on X-ray computed tomography explores the different experimental configurations for three-dimensional data acquisition as well as the fundamentals of three-dimensional data reconstruction, segmentation and analysis with examples across the physical and life sciences.

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X-ray computed tomography

Experimental investigation of the path-dependent strength and deformation behaviours of frozen loess

The freezing process of salinized soil is a complex, dynamic, and interactive hydro–thermal–salt–mechanical (HTSM) coupled physical phenomenon. In many recent studies, soil was assumed to ...

Theoretical and Numerical Analyses on Hydro–Thermal–Salt–Mechanical Interaction of Unsaturated Salinized Soil Subjected to Typical Unidirectional Freezing Process

Mineral filler, fine-grained mineral particles naturally present in or manufactured and added to aggregates play a significant role on the performance of asphalt mastic and asphalt mixtures. A clea...

Role of mineral filler in asphalt mixture

This paper aims to assess the characteristics of the deformation and strength behavior of frozen soils at different temperatures under monotonic and cyclic triaxial conditions. The deformation and failure patterns of the specimens change from ductility to brittleness with decreasing temperatures under both monotonic and cyclic loadings. The development of axial strain and stiffness with increasing number of cycles for the soils under cyclic loading is presented and analyzed in detail. A collapse behavior in strength and stiffness is observed in tests of frozen soils at − 5 °C, − 7 °C and − 9 °C. The difference in frictional sliding between the samples with high ductility and those with high brittleness is attributed to the different patterns of deformation and failure. The dynamic modulus is plotted versus axial strain, and the state where the stiffness begins to decrease is employed as the criterion of cyclic failure. The proposed criterion of cyclic failure is verified to be more suitable for frozen soils with high brittleness and seems to be consistent with the peak strength under monotonic loading. Finally, the cyclic stress ratios are plotted against the number of cycles up to this failure criterion, and the effect of temperatures on cyclic strength is evaluated.

Bingtang Song

Papers

Dynamic properties of frozen silty soils with different coarse-grained contents subjected to cyclic triaxial loading

Numerical analysis of coupled liquid water, vapor, stress and heat transport in unsaturated freezing soil

A new strength criterion for frozen soils considering the influence of temperature and coarse-grained contents

Study on effect of coarse-grained content on the mechanical properties of frozen mixed soils

Binary medium creep constitutive model for frozen soils based on homogenization theory