Publications

When AMT vehicles are driven under crowded conditions, the vehicle speed should be kept at a low level. In order to improve the speed tracking performance under this condition, the transmission output shaft speed is adopted to control the vehicle speed. The triple-step method is applied in this paper to improve the accuracy of the clutch slip control. The controller is composed of steady-state-like control, reference dynamics based feedforward control and tracking error feedback control, which utilize the feedforward information of the reference tracking trajectory and the feedback information of the vehicle speed. The plant model is built in software AMESim and the controller is built in MATLAB/Simulink. After the controller is deduced, it is validated through the co-simulation under various scenarios. The simulation results show that the vehicle speed tracking performance can be guaranteed under all of the scenarios, the tracking response is fast enough and the tracking error is small, illustrate the accurate control of the clutch and the effectiveness of the controller can be verified.

This paper presents a theoretical and experimental study on the attenuation coefficient of the ultrasonic expansion wave in concrete specimens made of different mixes and suffering from sulfate attack. The relationships between the attenuation coefficient, relaxation time, and the wave velocity of the elastic expansion wave were derived. By using simple ultrasonic techniques, the variation of the attenuation coefficient with time during the process of sulfate attack was determined experimentally. The results showed that the magnitude of the attenuation coefficient of concrete increased with time, reflecting damage evolution in the material caused by sulfate attack. This suggested that the damage caused by sulfate attack in concrete can be determined by using simple ultrasonic testing methods. Also, it was found that the concrete specimens with added fly ash had a better performance (reduced sulfate attack) than those with added fine ground slag.

Municipal solid waste incineration bottom ash (MSWI-BA) is a major by-product of municipal solid waste (MSW) incineration, leading to severe shortages of landfill sites in metropolitan cities. To achieve the resource utilization of MSWI-BA, this study explored the feasibility of producing ecological self-compacting mortar (eco-SCM) with MSWI-BA to realize recycling in building materials. First, it focused on the impact of the MSWI-BA proportion on eco-SCM with regard to workability, physical performance, mechanical performance, and durability. Second, it explored changes in the micro pore structure and micromorphology of eco-SCM under the impact of MSWI-BA. Finally, it evaluated the environmental friendliness and cost-effectiveness of eco-SCM. It was found that, (1) the mechanical strength of eco-SCM added with MSWI-BA was decreased. Eco-SCM added with MSWI-BA had compressive strength, flexural strength, and dynamic elastic modulus within the range of 37.71~54.76 MPa, 13.89~20.93 MPa, and 21.05~35.84 GPa, respectively; (2) Due to the addition of MSWI-BA, the chloride permeability of eco-SCM were deteriorated, but its durability was still satisfactory; (3) The environmental friendliness and economic performance of eco-SCM could be significantly improved, because of the addition of MSWI-BA. The energy consumption, carbon emissions, and costs of eco-SCM added with MSWI-BA at 40 wt% were decreased by 10.26%, 10.49%, and 26.50%, respectively; (4) Considering the changes in the workability, mechanical property, durability, environmental friendliness, and economic performance of eco-SCM added with MSWI-BA, MSWI-BA could be used to prepare eco-SCM and could be recycled in building materials.

To reduce carbon emissions during concrete production and enhance resource utilisation of incineration bottom ash (IBA), the incorporation of IBA as fine aggregate substitute for quartz sand in the preparation of environmentally friendly ultra-high performance concrete (EFUHPC) was evaluated. This study systematically examined the effects of varying IBA replacement ratios (0 %, 5 %, 10 %, 15 %, and 20 %) on the workability, mechanical properties, durability, microstructure, and toxicity of EFUHPC. It was observed that 1) the flexural strength, compressive strength, elastic modulus, and ultrasonic pulse velocity of EFUHPC were reduced by 3.11–17.47 % 3.72–12.89 % 3.75–12.96 % and 2.59–9.07 %, due to IBA incorporation, respectively. 2) the drying shrinkage and chloride migration coefficient of EFUHPC increased by 4.93–13.01 % and 10.65–24.36 %, due to IBA incorporation. 3) the porosity, cumulative pore volume and the threshold pore diameter of EFUHPC increased, due to IBA doping. 4) the EFUHPC can effectively solidify heavy metal ions in IBA. 5) using IBA to prepare EFUHPC can reduce its energy consumption, carbon emission and cost. The results of this research provide an effective direction to elucidate the potential of IBA in promoting sustainable development and environmental conservation.

No abstract is provided for this article.

This study aims to explore the dynamic response of ultra-high performance engineered cementitious composites (UHP-ECC) incorporating waste crumb rubber (CR) at various temperatures, focusing on its potential to enhance the resilience and sustainability of civil infrastructures against low-velocity impacts. To date, the impact behaviour of UHP-ECC under low temperatures has rarely been explored. Firstly, natural river sand and waste tyre CR was utilized to prepare the UHP-ECC. Then, a series of mechanical tests, including compression test, flexural test and uniaxial tensile test were carried out to investigate the static mechanical properties of rubberised UHP-ECCs. In addition, the effects of different waste CR incorporations (0%, 5%, 10%, and 15%) and various temperatures (25 °C, −5 °C, −30 °C, −50 °C, −100 °C and −196 °C) were comprehensively investigated by low-velocity impact tests with constant impact energy. Lastly, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) model was introduced to evaluate the overall performance of UHP-ECC. It was found that the use of river sand and CR significantly enhanced the tensile ductility and impact toughness of UHP-ECC. Impact energy primarily dissipates through damage such as matrix crack initiation, propagation, and fibre pull-out/rupture within the specimen. Adding CR notably decreased stress fluctuations during impact at room temperature, facilitating steady state energy absorption. Moreover, the time to reach peak impact force decreased with decreasing temperature across all UHP-ECC groups. At room temperature during impact process, fibre failure mode is dominated by pull-out failure, while lower temperatures lead to increased fibre rupture at the cracking surface. In low-temperature conditions, the impact response of rubberised UHP-ECC necessitates a comprehensive consideration of the synergistic effects, including material contraction, fibre bridging capacity, rubber phase transition, and water freezing.

Ink is one of the important material in printing process, its features, to a great extent, decide the printing quality, and ink viscosity is one of the main parameters, the value of the ink viscosity directly affects the quality of printing. In the case of other conditions are determined, the main factor of influencing the ink viscosity is temperature. In this paper, by using the Workbench CFX fluid simulation software, the ink temperature field of two extrusion ink rollers in printing press is analyzed by numerical simulation , the influence of the ink roller speed on ink temperature and the influence of ink roller thermal conductivity on the ink temperature are analyzed,.