Table of contents

Preface

2018 International Conference on Smart Materials Applications (ICSMA 2018) was held at Shaw Foundation Alumni House of National University of Singapore during 26-28 January 2018. The purpose of this conference was to provide a forum for accessing to the most up-to-date and authoritative knowledge from both industrial and academic worlds, sharing best practice in the field of smart materials analysis. The meeting provided an opportunity to highlight recent developments and to identify emerging and future areas of growth in this exciting field.

As a platform for technical exchange, each author has 15 minutes to introduce his or her research. In addition to the presentation, each author is encouraged to connect and exchange ideas with other scholars. Each contributed paper has been peer-reviewed by reviewers who were collected organizing and technical committee members as well as other experts in the field from different countries. The proceedings is not intended to be exhaustive about all areas of smart material applications. Rather, it focuses on some selected topics, especially material physics and computational materials science.

List of Statement of Peer Review available in this PDF.

List of Conference Chairs, Program Committee Chairs and Technical Committee are available in this PDF.

All papers published in this volume of IOP Conference Series: Materials Science and Engineering have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

Particle size has a significant effect on mechanical properties of particle reinforced metal matrix composites (PRMMCs). Here, the effect of particle size on mechanical properties of SiCp/Fe composite has been studied using a finite element (FE) model incorporated with the Taylor-based nonlocal theory (TNT) of plasticity, where the tested particle size is 5, 10, 16, 21, 28 and 40μm, respectively. The results indicate that the TNT-FE model overcomes the shortage of the traditional FE model, which cannot deal with the intrinsic size effect. With the particles of 20 vol.%, the simulated flow stress of the iron matrix composite reinforced by 16μm SiC particles is the highest and then follows the order of 28 > 5 > 10 > 21 > 40μm particle reinforced ones, close to the tendency of experimental results. A large area of compressive stress zone is observed in the matrix near the particles in the composites reinforced by 16 and 28μm particles, which implies that the matrix can be well protected during loading, so that the load-bearing capability is better. The purpose is to optimize mechanical property of SiCp/Fe composite by adjusting particle size and eventually to design PRMMCs from microstructural control.

The paper presents a numerical simulation about the damage process of the multiple countersunk bolted double-lap joints based on the cumulative damage theory which is widely used to estimate the mechanical strength of fastener joints, the Hashin's failure criterion, and the Tan's stiffness degradation model, and investigates the influence of the composite materials cumulative damage on the pin-load distribution. The numerical model of composite joints has been established in the commercial finite element software ANSYS to research the influence of the composite cumulative damage on the pin-load distribution, to assess the feasibility of integral analysis as well as to evaluate the error and rationality of traditional methods by applying the global analysis technology. The conclusions demonstrate that the results obtained with the method of composite cumulative damage considering properties degradation are close to those of conventional methods. The pin-load distribution is characterized by "Bolts at both ends bearing greater load, the central bolts bearing smaller load" during the whole loading process. Using conventional methods to study the pin-load distribution is easy and efficient to meet the needs of engineering application.

Cyanate/epoxy (CE/EP) was added with surface-modified silica (SiO₂) particles to form a composite system. Microstructure of the composites was observed to find the dispersion effect of SiO₂ particles in the CE/EP matrix. Thermal conductivity, thermal stability and dielectric properties were also tested to investigate the effects of SiO₂ particles. CE/EP-based composite with 50 wt% SiO₂ exhibited thermal conductivity of 0.492 W.m⁻¹.K⁻¹, thermal decomposition temperature of 420 °C and dielectric constant of 4.1 at 1 MHz.

Sandwich structures are gaining more importance in automobile industry due to its low weight, high flexural stiffness, and corrosion free properties. The composite structure with paper core sandwiched between two Polypropylene Glass-Filled (PP-GF) faces are being utilized for load floor of luggage compartments in passenger cars. To design, develop, and optimize the luggage floors, reliable Finite element (FE) methods are essential.

This study deals with developing a finite-element method to predict the behavior of the luggage floor of a typical Sedan car during ball impact test and static stiffness test. FE simulations are performed using LS-Dyna explicit code. Honeycomb core is modelled using solid elements and Modified honeycomb material model in LS-Dyna is assigned to the honeycomb structure. The two faces, bottom and top, are modelled using shell elements and modified-piecewise linear plasticity material model is assigned to them, respectively.

Experimental investigations are done for quasi-static four point bend test. FE simulations are performed for quasi-static four point bend test and validated with experimental results. Based on validated FE method, the ball impact test and static push test are simulated. Experiments are performed for the ball impact test and static push test. The results are compared and correlation between experiment and FE simulation is studied by comparing the deformation pattern, forces, and displacements. This developed FE method is for predicting the behavior of the luggage floor.

Composite materials are increasingly being relied upon for their light weight and high strength to weight ratios and form the backbone of the aerospace industry, which follows a Systems Engineering approach. This paper is an attempt to manifest such an approach at a relatively smaller scale for a composite UAV landing gear. The landing gear acts as a support structure for the fuselage during take-offs and landings and hence needs to be carefully designed, analyzed and manufactured. The strength and weight of a landing gear has to be optimized so as to adhere to the overall aerodynamics and structural integrity of the aerial system. This study is initiated with the design concept of the landing gear and the state of load being acted upon followed by appropriate composite material selection. An approximate number of layers are decided for the composite vacuum layup of the landing gear through iterative experimentation. The fibre orientation of the composite layers is instrumental in gauging the macro-mechanical performance of the composite, thus being the focal point of this study. To execute this, the extensional, coupling and bending stiffness matrices are computed in a mathematical model in MATLAB for different fibre orientations in response to the elastic constants of the fibre and matrix. The global and local strains and curvatures are calculated for a load case and the final combination is down-selected. Corresponding to the down-selected combination, the landing gear is finally fabricated, using Vacuum bag moulding.

Carbon fiber-reinforced polymer (CFRP) has been used in many aspects. During machining of CFRP damages are always brought in. Due to the brittleness property, the damages are closely related to the deformation in cutting area. In this study, a three-dimensional finite element model was established to study the deformation transformation in cutting area and the interactions of the deformation between two adjacent plies. An experiment was also conducted to measure cutting area deformation and sub-surface damage. The simulation results and experimental data were combined to analyze the correlation between cutting area deformation and sub-surface damage. The sub-surface damage was found have a positive relation with cutting area deformation. Based on the analyzing, a stacking strategy was proposed to reduce the damages in sub-surface. Then the optimization was verified in both numerical and experimental way.

Structural damage is an important criterion that can affect the system performance and degrade its ability from its original condition. When it comes to an aircraft, it is the wings of the aircraft that is prone to more damages compared to the body since the wings provide overall structure stability to the aircraft. It is thus mandatory to monitor the surface of the aircraft wing periodically in search of new damages or changes occurring in the wing structures. The term Health Monitoring systems is introduced in these precepts, that are useful in identifying damages in aircrafts, space crafts and mechanical infrastructures by taking periodic measurements with the help of various transmitters and sensors. Waves are allowed to propagate through the wing surface and the deviations occurring in the frequency of the waves are recorded and compared which helps in determining the various types of damages that occur. Yet another consideration is that the sensors embedded to the aircraft wing must be light weight, cost effective, user friendly at the same time provide accurate results for easy diagnosis of the problem. This is achieved by making use of lamb waves (also named as guided plate waves). The proposed work aims at the health monitoring of aerospace and mechanical structures, by using the wave propagation method and the use of piezo-electric wafer active sensors. Results have been validated by experimental and analytical calculations and the proposed method shows enhanced performance in the detection of cracks on the structural surfaces.

Because there is no gap between conduction band and valence band of graphene, it is difficult to achieve switching characteristics when transistors are fabricated. In order to open the graphene band gap, researchers have explored many methods, such as tailoring Shi Mocheng quantum dots, nanobelts, nano grids or laying graphene on a special substrate, one of the feasible ways is to regulate the electrical properties of graphene by doping. Through the analysis on the structure and properties of graphene band calculation, with the help of computer aided simulation, the ID and VG characteristics analysis of the Schottky barrier graphene field effect transistor (SBFET) and MOS structure of graphene field effect transistor (MOSFET) are investigated in this study. The results are of high reference value for the study of the structure and properties of graphene nanoribbons.

Gas sensor can be used to detect, monitor, monitor, analyze and alarm. It has very important application value in industry, national defense, food safety and medical examination. Among the gas sensors, the semiconductor resistance type gas sensor has many advantages, such as high sensitivity, fast response, small size, light weight, easy to carry, and so on. As one of the widely used gas sensing materials, SnO₂ has been a hot spot in the research and application in 60s, and it has been developing rapidly. SnO₂ is one of the most common gas sensitive materials, with physical and chemical properties of gas detection and stability; reversible adsorption and desorption time is short; low cost, energy saving and other advantages, is widely used in the detection of various gas sensitive devices. However, the disadvantages of high working temperature and poor selectivity of SnO₂ make it need to be further improved as gas sensitive material. The gas sensing mechanism of semiconductor gas sensitive material is mostly controlled by the surface, which is embodied in: increasing the specific surface area of the material and enhancing the gas sensing performance. At present, the main method of increasing the specific surface area of the material is nano scale. In this paper, the preparation and gas sensing properties of porous and hollow structure SnO₂ are mainly discussed on the basis of particle size. Porous structure facilitates the increase of the specific surface area of the material, providing a larger surface area and volume ratio for the material, which is of great benefit to the diffusion and transportation of the gas being measured. Nano hollow structure has a thin shell; the inner and outer surface provides a high surface area and volume ratio, so that the sensor has a faster response and recovery speed, and higher sensitivity. Using carbon micro spheres as hard templates, the structure of SnO₂ was successfully prepared by using different raw materials ratio and hydrothermal conditions. The composition and morphology of SnO₂ were characterized by XRD, SEM, TEM and so on. The study of gas sensitivity shows that the SnO₂ of the hollow classification structure can show good gas sensitivity, which has the advantages of high sensitivity, good selectivity and strong stability.

In this work, structure, electronic and optical parameters of germanium (Ge) atom substituted monatomic graphene are demonstrated through first-principles study (FPS) computations. The concentration of Ge atoms was changed from 2.5 % to 7.5 % and the effects of varying concentration on aforementioned properties were investigated. It is observed that, replacing C atoms with Ge in graphene leads to a finite bandgap opening at the Dirac K-point, thereby producing a direct bandgap semiconducting graphene. We also found that, Ge doping in graphene significantly changes its refractive index parameter. Moreover, Ge atom doping in graphene reduces the overall absorption coefficient, though it observes a considerable red-shift towards the visible region of spectrum. Graphene reflectivity improves in low lying energy region after Ge atom substitution in its lattice. These results can pave a new route for tuning the electronic and optical properties of graphene to make it functional for nanoelectronics and optoelectronic device applications.

The physical properties and mechanical behaviour of metals are determined by their microstructure frequently. The microstructure is referred to the size, shape and spatial arrangement of phases, grains, etc. These microstructure features have the mesoscopic length scale. How to obtain the desired microstructure is one main task of metal alloy design. However, it is difficult because the microstructure evolution is influenced by the chemical driving force during phase transformation, the composition of the alloy, etc. With the development of computing power and computer modelling, the computational material science is playing an important role in the microstructure design. Especially the kinetic phase field method is a powerful tool which is fast developed and widely used in these years. The phase field method is a phenomenological approach based on classical thermodynamic and kinetic theories. It describes a microstructure by using field variables. In this paper, the basic principle and application of this method are presented.

The comprehensive utilization of tailings mud has become a common concern of the society. The properties of tailings mud produced from Huzhou city were analyzed in this work. Moreover, porous ceramics with high strength were prepared by using the tailings mud as main raw material and adding a small amount of foaming agent. The results show that the foaming agent contents have a certain effect on the porosity and compressive strength of the porous ceramic samples. These results provided a certain theoretical basis for the comprehensive utilization of tailings mud and solve the pollution of tailings mud to the environment.

FRP (Fiber Reinforced Polymers) has been widely used in structure strengthening with the advantages of high strength, light weight, corrosion resistance and so on. FRP anchor is an effective anchoring method for external strengthening FRP laminate. In order to reduce cost and improve performance, B/C HFRP (hybrid of basalt fiber/carbon fiber reinforced polymer) anchor was made through mixing the basalt fiber with conventional CFRP anchors. The shear behavior and the anchoring performance of two kinds of FRP anchors under different diameter and arrangement methods were tested by several groups of experiments. The experimental results shew that the ultimate strength, material utilization and ductility of specimens were improved in different degrees, which indicated that it was practicable in concrete structures strengthening with this hybrid method.

Many studies have been carried out on natural fiber reinforced concrete for the different civil engineering applications. Wheat Straw Reinforced Concrete (WSRC) is recently studied for pavement applications which resulted in improved toughness. This will ultimately help in reducing the micro-shrinkage and fatigue cracking in rigid pavements. The overall aim of the research program is to improve the rigid pavement construction techniques by using locally available natural fibres. In this work, compressive strength of WSRC is investigated experimentally by varying fiber contents i.e. 1%, 2% and 3%, by mass of wet concrete. The properties of WSRC are compared with that of Plain Concrete (PC). The compressive behavior, strength, energies absorbed and toughness indices of PC and WSRC are determined and discussed. It is observed that, under the compressive loading, the fragments of PC specimen are chipped off while in WSRC specimen only cracks are formed. It is concluded that compressive toughness index of WSRC is 71% more than that of PC. Based on the conclusions made, WSRC shows favorable results, therefore, future recommendations are to focus on optimization and durability of WSRC.

In this paper, both thermal corrosion trace and electrothermal corrosion trace of aluminium-brass connectors are prepared by conducting simulation experiments under different heating temperatures and overload current conditions. The test samples are analyzed and described by metallographic analysis method, and the corresponding characteristic patterns are summarized, which provides the technical basis for the identification of the melting traces in the fire.

The present work shows the practical application of digital image correlation (DIC) technique for fracture toughness (K_IC) calculation. DIC is a non-contact, optical technique for measuring full-field displacements and strains by comparing an image of a deformed specimen surface to a reference image taken at un-deformed state. These captured images are correlated and the surface displacements are calculated from which the crack mouth opening displacements (CMOD) is determined. Results of DIC fracture toughness (K_IC) value is validated by comparison with fracture toughness (K_IC) value calculated from clip gauge. It is observed that the results obtained by DIC are in close agreement with the results obtained through conventional methods.

Multipass friction stir processing (MFSP) of the Ti-6Al-4V alloy was carried out at 600 tool rpm and 80 mm/min traverse speed. After first pass, the initial elongated α structure transformed to prior β grains, consisting of a mixture of acicular α'and very fine lamellar α colonies along with α layer grain boundary in stir zone (SZ). This subsequently transformed to equiaxed α grain via dynamic recrystallization (DRX) process. With the increase in the number of FSP passes the fraction of equiaxed α grains was found to increase, reaching almost fully equiaxed α structure in SZ upon completion of the fifth pass. Flow properties of MFSP Ti-6Al-4V alloy were investigated by differential strain rate test carried out at 927°C. There appears no significant variation in the strain rate sensitivity index (m ≥ 0.3) values between as received Ti-6Al-4V alloy and MFSP Ti-6Al-4V alloy specimens.

In this paper, the finite element model of asymmetric cold ring rolling for high-speed rail bearing inner ring is built by using ABAQUS software and the inner stress field of the ring metal during the whole cold ring rolling process is researched and analyzed, which reveals. The distribution of radial, axial, circumferential and equivalent stress at the bite rolling stage, the stable rolling stage and the fine rolling stage in the asymmetric cold rolling forming process for high-speed rail bearing inner ring were analyzed respectively. The stress in each direction of the ring was found to increase first and then decrease with each stage of cold rolling going. Finally, it tends to be stable. The stress on the contact area between the ring blank and the drive roll and the mandrel is obviously greater than that on the core of ring, and the stress in the core is more uniform.

The aim of this study was to design and fabricate a dental drill guide with built-in external irrigation mechanism for improved flow of irrigant at the drilling site to restrict the bone temperature below the threshold of thermal necrosis i.e. 47 °C during implant site preparation. This guide was compared with the conventional type 3D printed drill guide (commercially available in the market) in terms of heat generated while drilling.

Temperature was measured with K type thermocouple and data acquisition system using PPMA as a work piece instead of bone. Constant drilling load of 1.7 Kg was applied using a dedicated experimental setup. Drill speed was kept constant at 1200 rpm throughout the experimentation. Temperature was measured at the depths of 3, 7 and 11 mm with the help of thermocouples placed perpendicular to the drill axis. Incremental drilling as prescribed the drill manufacturer was performed. More than 10% improvement in maximum temperature was recorded at all the drilling locations when new drill guide was used.

This research aims at investigating the role and function of smart materials as a flexible approach in developing innovative products, and their impact on companies' performance. The paper first elaborates smart materials as a new trend in technology, by further identifying types of smart materials. Supplementary, some benefits of using smart materials in companies are named, especially for a case study on using smart paint and coating for producing innovative product. The concluding part responds to the question: How will product innovation by means of smart materials improve companies' performance?

Ball screws are the driving functional components most frequently used for the machining equipments. However, the precision positioning error of ball screws decide directly machining accuracy of machine tools. This paper aims to investigate the precision loss of ball screw considering full ball load distribution. The raceway wear model is built to predict the precision loss of ball screw in different structural parameters and operating parameters. Meanwhile, the precision loss rate is obtained and analyzed during the whole running life.

In order to shorten the design cycle of excavators and to meet the needs of users constantly updating key parameters in their designs, a reusable parametric design model of excavator sticks has been developed. Based on the WAVE function of Siemens NX, a parameterized model of large excavator stick is constructed, and a codeless reusable system is constructed by using NX / PTS powerful interactive operation function. At last, the reliability of the model is verified by the strength simulation. The entire system interface is intuitive and easy to operate, which greatly shortens the design cycle of the excavator stick and improves the design efficiency of the stick.

Previous studies focusing on analyzing components of automotive suspension system separately usually ignore the fact that each single component makes movement during operation resulting in simulation bias. This paper carries out a thorough analysis on the overall strength of a trailing arm torsion beam suspension system and compares the results with previous ones from analyzing single pieces. Consequently, significant improvements will be made in the design of suspension system.

In this paper, the deflection of a piezoelectric bimorph bender is controlled to track given time varying reference command solely utilizing direct acceleration measurement without integration. Novel estimator that directly applies acceleration measurement and controller that applies estimated state derivative signals have been developed in reciprocal state space (RSS) form. Simulations for the augmented system of both closed loop system and estimator have been carried out to successfully verify the proposed methods. The design approach in this paper is applicable to smart structures with accelerometers as sensors.

Silicone grease are widely applied in flange connections of gas-insulated switchgear (GIS) providing protection against flange and sealing O-ring corrosion and subsequent SF6 gas leakage. During GIS operation, grease bleeding phenomenon was frequently observed, which not only result in a poor appearance of flange surface but a potential SF6 leakage in the long-term application. In this paper, the possible reasons for this phenomenon is briefly discussed. In addition, the key parameters and outdoor performance of several commercial grease products were verified for a better understanding of its temperature resistance. It is shown that some grease products can have a better control on bleeding performance and should be more suitable for the outdoor GIS application.