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Sealing Performance and Optimization of a Subsea Pipeline Mechanical Connector

Chinese Journal of Mechanical Engineering 2018年第1期31卷 142-155页

作者： Li-Quan Wang Zong-Liang Wei Shao-Ming Yao Yu Guan Shao-Kai Li College of Mechanical and Electrical Engineering Harbin Engineering University Advanced Manufacturing Research Centre with Boeing The University of Sheffield

researchers seldom study the optimum design of a mechanical connector for subsea oil-gas pipeline based upon the sealing performance. An optimal design method of a novel subsea pipeline mechanical connector is presented. By analyzing the static metal sealing mechanism, the critical condition of the sealing performance is established for this connector and the formulation method of the contact pressure on the sealing surface is created. By the method the minimum mean contact pressure of the 8.625 inch connector is calculated as 361 MPa, which is the constraint condition in the optimum design of connector.The finite element model is created in ANSYS Parametric Design Language(APDL) and the structure is optimized by the zero-order method, with variance of contact pressure as the objective function, and mean contact pressures and plastic strains as constraint variables. The optimization shows that variances of contact pressure on two sealing surfaces decrease by 72.41% and 89.33%, respectively, and mean contact pressures increase by 31.18% and 52.84%, respectively. The comparison of the optimal connectors and non-optimal connectors in the water pressure experiments and bending experiments shows that the sealing ability of optimized connectors is much higher than the rated pressure of 4.5 MPa, and the optimal connectors don’t leak under the bending moment of 52.2 kN·m.This research provides the formulation to solve contact pressure on the sealing surface and a structure optimization method to design the connectors with various dimensions.

关键词： Mechanical connector Sealing mechanism Sealing performance Critical condition Minimum mean contact pressure Variance

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Experimental and numerical investigation of the abrasive waterjet machining of aluminum-7075-T6 for aerospace applications

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Advances in manufacturing 2021年第2期9卷 286-303页

作者： Joseck Nyaboro Mahmoud Ahmed Hassan El-Hofy Mohamed El-Hofy Department of Industrial and manufacturing Engineering Egypt-Japan University of Science and Technology(E-JUST)Alexandria 21934Egypt Department of Energy Resources Engineering Egypt-Japan University of Science and Technology(E-JUST)Alexandria 21934Egypt advanced manufacturing research centre(AMRC)with boeing The University of SheffieldRotherham S605TZUK

The machining of hard-to-cut materials with a high degree of precision and high surface quality is one of the most critical considerations when fabricating various state-of-the-art engineered components.In this investigation,a comprehensive three-dimensional model was developed and numerically simulated to predict kerf profiles and material removal rates while drilling the aluminum-7075-T6 aerospace alloy.Kerf profile and material removal prediction involved three stages:jet dynamic flow modeling,abrasive particle tracking,and erosion rate pre-diction.Experimental investigations were conducted to validate the developed model.The results indicate that the jet dynamic characteristics and flow of abrasive particles alter the kerf profiles,where the top kerf diameter increases with increasing jet pressure and standoff distance.The kerf depth and hole aspect ratio increase with jet pressure,but decrease with standoff distance and machining time.Crosssectional profiles were characterized by progressive edge rounding and parabolic shapes.Defects can be minimized by utilizing high jet pressure and small standoff distance.The material removal rate increases with increasing jet pressure,abrasive particle size,and exposure time,but decreases with increasing standoff distance.

关键词： Non-traditional machining Abrasive waterjet machining Computational fluid dynamics(CFD) Erosion modeling Kerf characteristics

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Expedient secondary functions of flexible piezoelectrics for biomedical energy harvesting

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Bioactive Materials 2023年第4期22卷 291-311页

作者： Yuan Wang Min Hong Jeffrey Venezuela Ting Liu Matthew Dargusch centre for advanced Materials Processing and manufacturing(AMPAM) The University of QueenslandBrisbaneQueensland4072Australia centre for Future Materials University of Southern QueenslandSpringfieldQueensland4300Australia

Flexible piezoelectrics realise the conversion between mechanical movements and electrical power by conformally attaching onto curvilinear surfaces,which are promising for energy harvesting of biomedical devices due to their sustainable body movements and/or deformations.Developing secondary functions of flexible piezoelectric energy harvesters is becoming increasingly significant in recent years via aiming at issues that cannot be addressed or mitigated by merely increasing piezoelectric efficiencies.These issues include loose interfacial contact and pucker generation by stretching,power shortage or instability induced by inadequate mechanical energy,and premature function degeneration or failure caused by fatigue fracture after cyclic deformations.Herein,the expedient secondary functions of flexible piezoelectrics to mitigate above issues are reviewed,including stretchability,hybrid energy harvesting,and self-healing.Efforts have been devoted to understanding the state-of-the-art strategies and their mechanisms of achieving secondary functions based on piezoelectric fundamentals.The link between structural characteristic and function performance is unravelled by providing insights into carefully selected progresses.The remaining challenges of developing secondary functions are proposed in the end with corresponding outlooks.The current work hopes to help and inspire future research in this promising field focusing on developing the secondary functions of flexible piezoelectric energy harvesters.

关键词： Flexible piezoelectrics Stretchable Hybrid energy harvesting Self-healing

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Robust Filtration Techniques in Geometrical Metrology and Their Comparison

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International Journal of Automation and computing 2013年第1期10卷 1-8页

作者： Shan Lou Wen-Han Zeng Xiang-Qian Jiang Paul J. Scott EPSRC centre for Innovative manufacturing in advanced Metrology University of Huddersfield

Filtration is one of the core elements of analysis tools in geometrical metrology. Filtration techniques are progressing along with the advancement of manufacturing technology. Modern filtration techniques are required to be robust against outliers, applicable to surfaces with complex geometry and reliable in whole range of measurement data. A comparison study is conducted to evaluate commonly used robust filtration techniques in the field of geometrical metrology, including the two-stage Gaussian filter, the robust Gaussian regression filter, the robust spline filter and morphological filters. They are compared in terms of four aspects： functionality, mathematical computation, capability and characterization parameters. As a result, this study offers metrologists a guideline to choose the appropriate filter for various applications.

关键词： Geometrical metrology robust Gaussian regression filter robust spline filter morphological filters surface roughness

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A review of the origin of equiaxed grains during solidification under mechanical stirring,vibration,electromagnetic,electric-current,and ultrasonic treatments

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Journal of Materials Science & Technology 2023年第13期144卷 243-265页

作者： Nagasivamuni Balasubramani Jeffrey Venezuela David StJohn Gui Wang Matthew Dargusch centre for advanced Materials Processing and manufacturing(AMPAM) School of Mechanical and Mining EngineeringUniversity of QueenslandSt.LuciaQLD 4072Australia

Refinement of grains and intermetallic phases in the as-solidified alloy structure offers uniform struc-tural properties,eliminates or minimizes common solidification defects,including segregation and hot cracking,and improves thermomechanical processing of wrought alloys.Melt processing by an external field is an efficient process for achieving refinement of the solidification structure of Al and Mg alloys without altering the alloy composition.A wide range of melt processing methods and solidification stud-ies(conventional,directional,and in-situ approaches)have been reported in the literature that explore the mechanism of refinement.Identifying the dominant grain refinement mechanism has been a focus of most investigations because significant variations exist according to the casting conditions and the type of applied external treatments.The origin of fine grains occurs through either one or a combination of heterogenous nucleation,fragmentation of dendrites and grains formed and then separated from the surface of the melt and mould wall under vibration or agitation.The first part of this review describes the prominent external field techniques and the mechanisms proposed for the origin of fine grains.The second part critically compares the current understanding of these grain refinement mechanisms to de-termine differences and commonalities to identify the factors that promote the formation of equiaxed zones occupying a large volume fraction of the casting.

关键词： Grain refinement Solidification Melt processing Equiaxed grains Intermetallic refinement

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Evaluation on the interface characteristics,thermal conductivity,and annealing effect of a hot-forged Cu-Ti/diamond composite

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Journal of Materials Science & Technology 2020年第14期47卷 7-14页

作者： Lei Lei Yu Su Leandro Bolzoni Fei Yang Waikato centre for advanced Materials and manufacturing School of EngineeringUniversity of WaikatoHamilton3240New Zealand

A Cu-1.5 wt.%Ti/Diamond(55 vol.%)composite was fabricated by hot forging from powder mixture of copper,titanium and diamond powders at 1050?C.A nano-thick TiC interfacial layer was formed between the diamond particle and copper matrix during forging,and it has an orientation relationship of(111)TiC//(002)Cu&[110]TiC//[110]Cuwith the copper matrix.HRTEM analysis suggests that TiC is semicoherently bond with copper matrix,which helps reduce phonon scattering at the TiC/Cu interface and facilitates the heat transfer,further leading to the hot-forged copper/diamond composite(referred as to Cu-Ti/Dia-0)has a thermal conductivity of 410 W/m K,and this is about 74%of theoretical thermal conductivity of hot-forged copper/composite(552 W/m K).However,the formation of thin amorphous carbon layer in diamond particle(next to the interfacial TiC layer)and deformed structure in the copper matrix have adverse effect on the thermal conductivity of Cu-Ti/Dia-0 composite.800℃-annealing eliminates the discrepancy in TiC interface morphology between the diamond-{100}and-{111}facets of Cu-Ti/Dia-0 composite,but causes TiC particles coarsening and agglomerating for the Cu-Ti/Dia-2 composite and interfacial layer cracking and spallation for the Cu-Ti/Dia-1 composite.In addition,a large amount of graphite was formed by titanium-induced diamond graphitization in the Cu-Ti/Dia-2 composite.All these factors deteriorate the heat transfer behavior for the annealed Cu-Ti/Dia composites.Appropriate heat treatment needs to be continually investigated to improve the thermal conductivity of hot-forged CuTi/Dia composite by eliminating deformed structure in the copper matrix with limit/without impacts on the formed TiC interfacial layer.

关键词： Copper/diamond composite Hot forging Interface characteristics Thermal conductivity Heat treatment

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Indirect approach for predicting cutting force coefficients and power consumption in milling process

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Advances in manufacturing 2022年第1期10卷 101-113页

作者： Kai-Ning Shi Ning Liu Cong-Le Liu Jun-Xue Ren Shan-Shan Yang Wei Chit Tan Key Laboratory of High Performance manufacturing for Aero Engine Department of Mechanical EngineeringMinistry of Industry and Information TechnologyNorthwestern Polytechnical UniversityXi’an 710072People’s Republic of China Engineering research centre of advanced manufacturing Technology for Aero Engine Department of Mechanical EngineeringMinistry of EducationNorthwestern Polytechnical UniversityXi’an 710072People’s Republic of China Virtual manufacturing Group Smart Manufacturing DivisionAdvanced Remanufacturing and Technology Centre3 Cleantech Loop#01-01CleanTech TwoSingapore 637143Singapore

Accurate energy consumption modeling is an essential prerequisite for sustainable manufacturing.Recently,cutting-power-based models have garnered significant attention,as they can provide more comprehensive information regarding the machining energy consumption pattern.However,their implementation is challenging because new cutting force coefficients are typically required to address new workpiece materials.Traditionally,cutting force coefficients are calculated at a high operation cost as a dynamometer must be used.Hence,a novel indirect approach for estimating the cutting force coefficients of a new tool-workpiece pair is proposed herein.The key idea is to convert the cutting force coefficient calculation problem into an optimization problem,whose solution can be effectively obtained using the proposed simulated annealing algorithm.Subsequently,the cutting force coefficients for a new tool-workpiece pair can be estimated from a pre-calibrated energy consumption model.Machining experiments performed using different machine tools clearly demonstrate the effectiveness of the developed approach.Comparative studies with measured cutting force coefficients reveal the decent accuracy of the approach in terms of both energy consumption prediction and instantaneous cutting force prediction.The proposed approach can provide an accurate and reliable estimation of cutting force coefficients for new workpiece materials while avoiding operational or economic problems encountered in traditional force monitoring methods involving dynamometers.Therefore,this study may significantly advance the development of sustainable manufacturing.

关键词： Sustainable manufacturing Cutting force coefficients Energy consumption Machining processSimulated annealing

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Current understanding of the origin of equiaxed grains in pure metals during ultrasonic solidification and a comparison of grain formation processes with low frequency vibration,pulsed magnetic and electric-current pulse techniques

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Journal of Materials Science & Technology 2021年第6期65卷 38-53页

作者： Nagasivamuni Balasubramani Gui Wang David H.St John Matthew S.Dargusch centre for advanced Materials Processing and manufacturing(AMPAM) School of Mechanical and Mining EngineeringUniversity of QueenslandSt Lucia

The formation of fine,non-dendritic equiaxed grains throughout a casting without the addition of refiners(i.***.independent of alloy chemistry),is made possible by using ultrasonic,magnetic or pulsed magnetic and electric current pulse techniques.The dominant mechanisms proposed for the grain refinement produced during the application of an external field are cavitation phenomena assisted nucleation or fragmentation of dendrites(ultrasonic field),wall crystals arising from the cold surface of the mould(electric current pulse,magnetic and pulsed magnetic fields).In all these cases fluid flow provides an additional contribution(e.***.reduced temperature gradients,growth rate and remelting of dendrites)to maintaining an equiaxed grain structure.The origin of equiaxed grains under an external field also depends on the casting conditions(volume and shape of casting)and the type of alloy other than the mechanisms specific to a particular technique.The current work aims to provide a detailed understanding of the various factors and mechanisms that influence the grain refinement achieved during the solidification of pure metals(magnesium and zinc)subjected to Ultra Sonic Treatment(UST).The role of the temperature range of UST application,time duration and an unpreheated sonotrode are examined with respect to the origin,evolution of equiaxed grain structure,morphology and the columnar to equiaxed transition.The origin of grains was analysed from three fundamental aspects that contribute to refinement(i)heterogeneous nucleation(ii)fragmentation of existing dendrites and(iii)grains produced from the colder surfaces(arising from mould walls or vibrating surfaces as wall crystals).A comparison of UST refinement with mechanical,low-frequency vibration,electric current pulse and magnetic field solidification of pure metals has also been provided to highlight the importance of the cold surfaces(sonotrode and mould wall)in influencing grain refinement.

关键词： Ultrasonic treatment Grain refinement Equiaxed grains Magnesium Zinc Solidification

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Three-dimensional printing of biomaterials for bonetissue engineering: a review

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Frontiers of Materials Science 2023年第2期17卷 1-43页

作者： Ahmed El-Fiqi Glass research Department Advanced Materials Technology and Mineral Resources Research InstituteNational Research CentreCairo 12622Egypt

Processing biomaterials into porous scaffolds for bone tissueengineering is a critical and a key step in defining and controlling their physicochemical,mechanical,and biological properties.Biomaterials such as polymers are commonlyprocessed into porous scaffolds using conventional processing techniques,e.g.,saltleaching.However,these traditional techniques have shown unavoidable limitations andseveral shortcomings.For instance,tissue-engineered porous scaffolds with a complexthree-dimensional(3D)geometric architecture mimicking the complexity of theextracellular matrix of native tissues and with the ability to fit into irregular tissue defectscannot be produced using the conventional processing techniques.3D printing hasrecently emerged as an advanced processing technology that enables the processing ofbiomaterials into 3D porous scaffolds with highly complex architectures and tunableshapes to precisely fit into irregular and complex tissue defects.3D printing providescomputer-based layer-by-layer additive manufacturing processes of highly precise andcomplex 3D structures with well-defined porosity and controlled mechanical propertiesin a highly reproducible manner.Furthermore,3D printing technology provides anaccurate patient-specific tissue defect model and enables the fabrication of a patientspecifictissue-engineered porous scaffold with pre-customized properties.

关键词： 3D printing biomaterial ink printability 3D printing technique 3D printed scaffold bone tissue engineering

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Perceptions and Attitudes Towards Shoulder Padding and Shoulder Injury in Rugby Union

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Journal of Science in Sport and Exercise 2022年第1期4卷 66-73页

作者： Angus Hughes Matt Carré Heather Driscoll Department of Mechanical Engineering The University of SheffieldSheffield S102TNUK advanced manufacturing research centre The University of SheffieldSheffield S605TZUK

Purpose To develop an understanding of the role of shoulder padding in rugby union by investigating player perceptions and attitudes towards shoulder padding and extending research into shoulder injuries in rugby.Methods An online survey was distributed to past and current rugby players over 13 years old in 2018.Questions related to the participants’demographic,attitudes to shoulder padding and shoulder injury history.Results Six hundred and sixteen rugby players responded to the survey;66.1%of respondents had worn shoulder padding at some point.The age group 24-29 years old(ΔR^(2)=0.03,B=−0.53,P=0.015)had an inverse association with padding effectiveness while playing experience groups 1-2 years(ΔR^(2)=0.03,B=0.8,P=0.032),3-5 years(ΔR^(2)=0.03,B=0.70,P=0.002)and 6-9 years(ΔR^(2)=0.03,B=0.41,P=0)had a positive association.There are 37.1%of respondents consider-ing shoulder padding to be effective at preventing cuts and abrasions with 21.9%finding it very effective;50.3%considered it to be effective or very effective(9.7%)at preventing contusion;45.5%wore padding for injury prevention,while 19.2%wore padding to protect from reoccurring injury.Sprain/ligament damage(57.5%)and bruising(55.5%)were the most com-monly reported injuries.Conclusions The primary reason for wearing shoulder padding was as a means of injury prevention.research should focus on quantifying the injury preventive capabilities of shoulder padding.Bruising,cuts and abrasion injuries to the shoulder are prevalent presenting new findings that these injuries are underreported.

关键词： Rugby union Shoulder padding Protective equipment Epidemiology Attitudes

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