As recently demonstrated, after programming, thermo-responsive shape memory polymers can exhibit the multi-shape memory effect (SME) upon heating. In addition, it is confirmed that the temperature corresponding to the maximum recovery stress in constrained recovery is roughly the temperature at which pre-deformation is conducted, a phenomenon known as the temperature memory effect (TME). In this paper, we propose a framework to investigate the underlying mechanisms behind both effects and provide the conditions for the TME. According to this framework, we can achieve fully controllable shape recovery following a very complicated sequence in a continuous manner.

The world is rich in marine resources, and the use of seawater, sea sand and coral instead of fresh water, river sand and gravel can solve problems such as the scarcity of traditional materials for marine engineering construction. Additionally, fibre-reinforced polymer (FRP) bars have demonstrated excellent corrosion resistance performance, which can effectively solve the problem of the corrosion of steel in harsh marine environments. To study the bond performance between FRP bars and sea sand coral concrete (SSCC), 72 specimens of direct Pull-out were designed, and relevant tests were carried out to explore the effects of fibre types, bar diameters, bond lengths and SSCC strength grades. The results show that the bond strength between carbon fibre-reinforced polymer (CFRP) bars and SSCC was higher than that of basalt fibre-reinforced polymer (BFRP) bars and glass fibre-reinforced polymer (GFRP) bars. The splitting damage pattern occurred in most of the specimens; the bond strength between FRP bars and SSCC decreased with increasing diameter and bond length of FRP bars but increased with increasing SSCC strength grade. As a result, by fitting the bond-slip curves obtained from the tests, the bond-slip constitutive relationship between FRP bars and SSCC specimens was obtained, which clearly and precisely represents the bond failure process of SSCC with FRP bar reinforcement.

Current available shear-thickening fluid (STFs) may suffer from issues such as unsatisfactory energy dissipation performance and unstable dynamic stability for practical engineering applications. This paper investigates the innovated compounded STFs which is fabricated by mixing needle-like carbon fiber powder (CFP) and silicon dioxide (SiO₂) into polyethylene glycol (PEG) under proper synthesis conditions. The microstructure and rheological properties of the compounded STFs, namely CFP- SiO₂/PEG, are investigated. The interaction between CFP and SiO₂ and the shear-induced microstructure are analysed using scanning electron microscopy (SEM). Steady-state rheological tests reveal that compounded STFs with different mass ratios exhibiting significant rheological behaviour and shear-thickening (ST) effects. The peak viscosity is demonstrated to be increased from 51.59 Pa·s (monodispersed STFs) to 574.74 Pa·s (compounded STFs), and the critical shear rate decreased from 79.42 s^-1 to 10.00 s^-1, when the mass fraction of CFP is set at 0.2%. The peak viscosity of the compounded STFs is shown to be increased by 313.96%, when the plate spacing is increased from 0.25mm to 1.00mm. The dynamic rheological analysis shows that the compounded STFs exhibiting excellent energy dissipation capacity at different stages. More importantly, the modulus instability and shear-thinning problems of monodispersed STFs could be significantly improved. According to the results, the key performance index of the CFP/SiO₂-PEG compounded STFs is demonstrated be improved by ten times or even higher. This work presents a novel type of STFs with high energy dissipation capacity and high dynamic stability for the application of shear thickening fluids composite in engineering practice.

This research focuses on a desensitization method to develop a wide-range FBG sensor for extra-large strain monitoring, which is an essential requirement in large scale infrastructures or for some special occasions. Under appropriate hypotheses, the strain transfer distribution of wide-range FBG sensor based on the shear-lag theory is conducted to improve the accuracy of extra-large strain measurements. It is also discussed how the elastic modulus of adhesive layer affects the strain transfer rate. Two prototypes in different monitoring ranges are designed and fabricated by two layers of steel pipe encapsulation. The presented theoretical model is verified by experimental results. Moreover, it is demonstrated that experimentation in regards to the calibration of the wide-range FBG sensor, improved the amplification coefficient up to 2.08 times and 3.88 times, respectively. The static errors are both calculated and analyzed in this experiment. The wide-range FBG strain sensor shows favourable linearity and stability, which is an excellent property of sensors for extra-large strain monitoring.