Shape memory alloys (SMAs) are a class of functional materials with the ability to regain their original shapes after a large inelastic deformation upon external stimuli. In recent years, SMAs have been employed in many applications in different fields. Nitinol is the most widely used SMA due to its outstanding properties such as shape memory effect, superelasticity, biocompatibility, and corrosion resistance among other types of SMAs. Some efforts are also made to implement SMAs on filtration devices that require deployable structures. This motivates the authors to write a review of the recent developments in the field of SMA based filtration devices as far as the use of SMAs is concerned. The present work provides a brief overview of history and basics of SMAs. This paper then reviews and discusses the recent progress and applications of SMA based filtration devices and the challenges of these filtration devices. It is found that most devices are made of nitinol. The aim of this paper is to introduce SMA based filtration devices and promote future developments of functional filtration applications.

Splash-lubricated gearboxes are widely used in many industries. Contaminant removal systems are rarely employed in splash-lubricated gearboxes, such as some gearboxes are used in helicopters and mining machines. The maintenance of lubrication systems in those machines relies on periodic onsite inspection and lubricant change. However, wear debris generated during operation will suspend in lubricant and cause damage to contacting surfaces of gearbox’s components. In this first part of a two-part paper, a novel light-weight passive filtration system that utilises gravitational sedimentation and shape memory alloys is presented for unfiltered splash-lubricated gearboxes. A predictive model is developed for the estimation of flake-like wear particles’ settling behavior in the lubricant. Experiments based on a simplified test rig are also conducted to validate the theoretical results. This mathematical model can also be used to elucidate the impact of sedimentation time of wear particles on the cleanliness of the lubricant after the installation of passive filtration system.

Concrete structures can suffer from water permeating under stresses. This paper investigates the surface water permeability of reinforced concrete elements subjected to uniaxial tension. A testing system was developed to combine a conventional loading machine with a surface permeameter. To eliminate the effect of initial absorption of water, calibration tests were conducted on plain concrete samples with different surface saturated states. The experiment presented is designed to test the surface water permeability of a structural member under uniaxial tension. Specimens were reinforced centrally with different sizes of steel bar and fabricated with normal‐strength and high‐strength concrete. A uniaxial tensile load was applied from 0.10 to 0.80 of estimated ultimate cracking load in 0.10 increments. At the same time, water permeability was measured at each load step. Test results give the relationship between water permeability of concrete member and tensile load levels.

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Concrete member is usually stressed in structure. To test permeable behavior of concrete under load is significant in clarifying this characteristic. Currently, most of the methods measure the permeability of concrete specimen without stress. This paper describes a method that measures permeability of concrete subject to a uniaxial tension load. The main components of the test device include two parts. One is tension loading system, and the other is permeability system. The concrete member with 100×100×1000mm is designed to be the sample. A uniaxial tension load could be applied to the prism concrete specimen and the load was allowed to increase by steps until failure. Autoclam is adopted as permeability system. At each ground of the tension load the volumetric water flow through specimen is recorded with data acquisition automatically. The relationship between water permeability and increasing stress could be obtained with the suggested method.