Journal of Zhejiang University-SCIENCE A

https://link.springer.com/journal/11582

List of Papers (Total 303)

Finite element modeling of superplastic co-doped yttria-stabilized tetragonal-zirconia polycrystals

Yttria-stabilized tetragonal-zirconia polycrystals (Y-TZP) have been shown to have superplastic properties at high temperatures, opening a way for the manufacture of complex pieces for industrial applications by a variety of techniques. However, before that is possible, it is important to analyze the deformation and fracture mechanisms at a macroscopic level based on continuum...

A growth-based topology optimizer for stiffness design of continuum structures under harmonic force excitation

The aim of this study is to explore the potential of various plant ramifications as concept generators for creating a brand topology optimization solution for stiffness design of continuum structures under harmonic force excitations. Firstly, a mathematical model is built to identify analytical laws that underlie the optimality of the effective but individual design rules of...

Vertical vibration of a large diameter pile embedded in inhomogeneous soil based on the Rayleigh-Love rod theory

The vertical vibration of a large diameter pile embedded in inhomogeneous soil with hysteretic type damping is investigated based on the 3D axisymmetric model. Firstly, the pile is assumed to be a Rayleigh-Love rod with the consideration of its transverse inertia effect. Following this assumption, the pile-soil system is divided into several segments according to the...

A structural reliability-based sensitivity analysis method using particles swarm optimization: relative convergence rate

This paper proposes a novel reliability-based sensitivity analysis (SA) method, namely relative convergence rate of random variables using particles swarm optimization (PSO). The convergence rate of a random variable during the optimum evolution process reflects the sensitivity of the objective function with respect to the random variables. An optimized group strategy is proposed...

Framework of mechanical symmetry breaking theory and its application to innovative design

Symmetry breaking phenomena exist in many mechanical products. Based on an analysis of the variation in physical features in several design examples, mechanical symmetry breaking concept systems that consist of general requirements, working principles, and cross-scale mechanical structures are established from the macro to micro levels and in both machine assembly and the design...

Generation III pressurized water reactors and China’s nuclear power

The design philosophy, overall performance, safety, and economy of three typical generation III (GIII) pressurized water reactors, EPR, AES2006, and CAP1400, are analyzed comprehensively in this paper. Based on comparison with and the lessons learned from the Fukushima nuclear accident, we forecast a future reactor for China’s commercial nuclear power plant. Moreover, we put...

Direct reliability-based design optimization of uncertain structures with interval parameters

In order to enhance the reliability of an uncertain structure with interval parameters and reduce its chance of function failure under potentially critical conditions, an interval reliability-based design optimization model is constructed. With the introduction of a unified formula for efficiently computing interval reliability, a new concept of the degree of interval reliability...

Packing and film thickness theories for the mix design of high-performance concrete

A high-performance concrete (HPC) is required to have superior performance in various aspects such as workability, strength, durability, dimensional stability, segregation stability, and passing ability. The mix design of HPC is rather complicated because the number of ingredients in HPC is usually more than those in conventional concrete and some of the required properties are...

Membrane fouling behavior and microbial community succession in a submerged membrane bioreactor treating harbor oily wastewater

A membrane bioreactor (MBR) was established for treating harbor oily wastewater. It showed good removal performance for chemical oxygen demand (COD), oil content, suspended solids (SS), and other pollutants. However, serious membrane fouling occurred. It was recognized that the extracellular polymeric substances (EPS) accumulated on the membrane surface, especially the proteins...

Design of an ultrasonic motor with multi-vibrators

This paper presents and verifies a new idea for constructing an ultrasonic motor (USM). The stator contains several vibrators fabricated by bonding piezoelectric ceramics (PZTs) to a metal base. When two alternating current (AC) voltages with a 90° phase difference are applied to the PZTs, longitudinal and bending modes are excited in the vibrator. The bending vibrations of the...

A study of airfoil parameterization, modeling, and optimization based on the computational fluid dynamics method

An excellent airfoil with a high lift-to-drag ratio may decrease oil consumption and enhance the voyage. Based on NACA 0012, an improved airfoil is explored in this paper. The class/shape function transformation has been proved to be a good method for airfoil parameterization, and in this paper it is modified to improve imitation accuracy. The computational fluid dynamics method...

Quasi 1D modeling of two-phase flow and deposit formation for urea-selective catalytic reduction systems

A quasi 1D model of two-phase flow for a urea-selective catalytic reduction (SCR) system is developed which can calculate not only the generation of reducing agent but also the formation of deposits in the exhaust pipe. The gas phase flow is solved through Euler method, variables are stored on staggered grids, and the semi-implicit method for pressure-linked equation (SIMPLE...

Laboratory and numerical study on an enhanced evaporation process in a loess soil column subjected to heating

The water vapor diffusion can be enhanced by the heating from municipal solid waste, and significantly impact the evaporation process in the earthen final cover. The parameters associated with the water vapor diffusion are usually measured by using the instantaneous profile method. This method is very time-consuming because the drying process lasts a long time. In this study, a...

Trend setting research in “blue” and “green” directions

概要中国自然科学基金委员在2016 年6 月14 日正式发布的《国家自然科学基金“十三五”发展规划》中明确指出,未来5 年,基金委将重点支持与“绿色“(以环保为代表)和“蓝色”(以海洋、能源能为代表)相关的交叉学科研究。由于岩土地基是大多数环保和能源相关活动(如城市废弃物的填埋和覆盖、液岩气和海底天然气水合物的安全开采)的最终承载者,岩土工程师和环保、能源相关领域的学者在过去的30 年里紧密合作,以应对人类在这两大领域所面对的严峻挑战,同时也催生了两个重要的交叉学科,即环境岩土和能源岩土。可以预见,随着环境污染和能源短缺等问题的日益凸显,针对环境岩土和能源岩土的深入研究显得愈发重要。以此为背景,香港科技大学主办了“第一届环境岩土和能源岩土国际会议(GeGe2015...

Field studies of a technique to mitigate ground settlement of operating highways

In the eastern coastal region of China, many operating highways built over soft ground are vulnerable to severe post-construction settlement. In this study, a technique using jet grouted piles is developed to mitigate post-construction settlement. The piles are installed by drilling boreholes throughout the embankment. The principal stages of the construction process are...

Time- and stress-dependent model for predicting moisture retention capacity of high-food-waste-content municipal solid waste: based on experimental evidence

Moisture retention capacity (MRC) is a key parameter for the prediction of leachate production of a municipal solid waste (MSW) pile. In this paper, five sets of laboratory tests were conducted in compression cells to characterize the variation of MRC with degradation time and overburden stress. Set A was conducted on the fresh high-food-waste-content (HFWC)-MSW under different...

Field measurement of gas permeability of compacted loess used as an earthen final cover for a municipal solid waste landfill

The use of loess as an earthen final cover material is promising in northwest China which has an arid and semi-arid climate. A full-scale testing facility with an area 30 m long by 20 m wide was constructed at the Xi’an landfill of municipal solid wastes to investigate the performance of an inclined capillary barrier cover. The cover consisted of a compacted loess layer underlain...

Mitigation of soil liquefaction using microbially induced desaturation

Soil liquefaction can cause disastrous consequences to buildings and human lives. Regular countermeasures against soil liquefaction are often overly expensive for normal buildings and structures. This could be the major reason that liquefaction induced damage is still widely encountered in large- and mid-size earthquakes in recent years. In this paper, a new method for the...

A novel multi-objective optimization method for the pressurized reservoir in hydraulic robotics

The pressurized reservoir is a closed hydraulic tank which plays a significant role in enhancing the capabilities of hydraulic driven robotics. The spring pressurized reservoir adopted in this paper requires comprehensive performance, such as weight, size, fluid volume, and pressure, which is hard to balance. A novel interactive multi-objective optimization approach, the feasible...

Design procedure for thin three-layer plates made of a depleted material

The efficiency of a long-span structure relies on how material is locally distributed within a fixed structural shape. In this paper a design procedure for thin plates made of three layers of a depleted material subject to a distributed vertical load is proposed. The investigation is driven by the idea of the optimal material organization and has the objective of maximizing the...

A numerical study on the high-velocity impact behavior of pressure pipes

Pressure pipes are widely used in modern industry with some in potentially dangerous situations of explosion and impact. The security problems of these pipes when subjected to impact have attracted a lot of attention. A non-linear numerical model has therefore been developed to investigate the dynamic behavior of pressure pipes subjected to high-velocity impact. A high strain...

Typical dielectric elastomer structures: dynamics and application in structural vibration control

In recent years, dielectric elastomer (DE) structures have received great attention in various fields of engineering, such as artificial muscle, soft robot, resonator, and structural vibration control, due to its prominent advantages. In the present paper, the theoretical and experimental research into the dynamical behavior of DE structures and their application for vibration...