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The present work performed a combined experimental and numerical investigation of the catalytic ignition and combustion characteristics for a hybrid rocket engine (HRE) using 90% hydrogen peroxide ([Formula: see text]) with a paraffin-based fuel as the propellant system. The variation of the [Formula: see text] decomposition temperature used as the analytical premise was monitored by a thermocouple and laser absorption spectroscopy based on water absorption. The effects of preheating, the number of silver mesh layers, and the usage count for the catalytic bed on the [Formula: see text] decomposition characteristics were analyzed. A preheated 60-layer silver catalyst bed provided the best decomposition performance, including the shortest catalytic decomposition delay time and the highest decomposition efficiency. A two-dimensional numerical model was built to determine the effect of decomposition efficiency decay on the HRE combustion characteristics. Variations in the combustion temperature, combustion chamber pressure, and product distribution were compared for [Formula: see text] decomposition efficiencies ranging from 70 to 100%. As the decomposition efficiency of [Formula: see text] decreased to 80%, part of the oxidizer was blown out the chamber before participating in the combustion, yielding a significant decline in the combustion performance of the hybrid rocket engine. Static firing tests were also used to determine the catalytic ignition and reignition performance of the HRE. The results showed that the performance of the catalytic bed was stable while the reignition process was rapid without a pressure peak.

The flame dynamics in the combustion chamber of a hybrid rocket motor were visualized using novel chemiluminescence imaging. A multidirectional visualization system employing [Formula: see text] endoscopes generated images based on methylidyne chemiluminescence (CH*), with one endoscope in the precombustion chamber and two in the postcombustion chamber. Images were collected with a high-speed camera using a 1 ms exposure and a 1 kHz frame rate. Fuel grains having a helical or a conventional circular port structures were assessed, and combustion trials were conducted using a laboratory-scale hybrid rocket motor with oxygen as the oxidizer at mass flow rates from 10.43 to [Formula: see text]: equivalent to combustion chamber pressures ranging from 0.7 to 1.24 MPa. Flame structures were observed during the ignition, combustion, and shutdown stages; and the helical grain generated a larger, more intense flame zone. A proper orthogonal decomposition analysis showed that the helical grains also produced a greater degree of turbulence and stronger oscillations. These results confirm that a helical structure increases the flow turbulence and convective heat transfer in the combustion chamber. These effects lead to higher regression rates and better mixing efficiency that may, in turn, provide greater combustion efficiency at optimized oxidizer/fuel ratios.

In situ monitoring during the selective laser melting (SLM) process is a promising solution to mitigate defects and improve the quality of as-built parts. However, the existing monitoring platform lacks collaborative control of the process monitoring components, and as a result, it cannot realize a real-time and accurate signal acquisition at a close distance and multiple angles during the whole printing process. In this paper, driven by multiple motors, an off-axis monitoring platform is constructed that enables movement in conjunction with the scraper and laser beam. A fuzzy control-based velocity optimization is proposed to avoid the shock effect on the imaging quality of the CMOS camera and the collision of the scraper and laser. The error between the current location and target location of the molten pool is utilized as the input of the fuzzy controller. Then, the parameters of the PI controller of the stepping motor are dynamically adjusted. ADAMS and SIMULINK co-simulation are conducted to verify the feasibility of the fuzzy algorithm. Finally, the experiment of collaborative motion and the responses of each module are conducted. The results show that with the proposed collaborative platform, the response speed of the system is improved by about 49.6%, and the initial speed of the motor is decreased by about 12.6%, thus avoiding excessive acceleration of the motor. The response time of each motor is ahead of schedule by about 31.8%, which meets the requirements of motion response for SLM process monitoring.

The properties of modified conventional wrought aluminum alloys cannot be significantly enhanced by normal post-heat treatment in that the fine-grained strengthening, arising from high cooling rate in SLM, is underutilized. In this work, compared with the normal T6 heat treatment, a novel simple direct aging regime was proposed to maintain the grain-boundary strengthening and to utilize the precipitation strengthening of secondary Al3Zr. It was found that a heterogeneous grain structure, which consisted of ultrafine equiaxed (∼0.82 μm) and columnar (∼1.80 μm) grains at the bottom and top of molten pool, respectively, was formed in the SLM processed sample. After direct aging (DA), the ultrafine grains were maintained and a mass of spherical coherent L12-Al3Zr particles with a mean radius of approximately 1.15 nm was precipitated. In contrast, after solution treatment and aging (STA), a significant grain coarsening occurred in the equiaxed grain region. Meanwhile, the coarsening L12-Al3Zr particles, nano-sized S′ phases and GPB zones were detected in the STA sample. This subsequently induced that the yield strength of the DA sample (∼435 MPa) was higher than that of the STA sample (∼402 MPa) owing to the grain boundary strengthening and precipitation strengthening. Both the STA and DA samples exhibited a higher strength than that of the other SLMed Al-Cu-Mg series alloys; this was comparable to that of the wrought AA2024-T6 alloy (∼393 MPa). Both the STA and DA samples exhibited a higher strength than that of the other SLMed Al-Cu-Mg series alloys; this was comparable to that of the wrought AA2024-T6 alloy (∼393 MPa).

The synergistic effect of Mo and Zr additions on microstructure evolution, room-temperature fracture toughness and microhardness of Nb-22Ti-15Si-xMo-yZr (x = 4,8, y = 3,6) alloys manufactured by laser directed energy deposited (L-DED) have been investigated. The major phases in as-deposited 4Mo-3Zr alloy are Nb solid solution (Nbss), Nb3Si and γ-Nb5Si3. The Nb3Si phases disappear with increasing Mo content to 8 at.% or increasing Zr content to 6%. γ-Nb5Si3 precipitates formed in the Nbss of as-deposited xMo-yZr alloys due to the cyclic re-heating, and the γ-Nb5Si3 precipitates and Nbss matrix exhibits orientation relationship (OR) of [001]Nbss//[ 1 ¯ 112]γ and (110)Nbss//(01 1 ¯ 0)γ in as-deposited 4Mo-6Zr alloy. The microstructure of xMo-yZr alloys became relative homogeneity and the Nbss matrix showed the better continuity after the heat treatment (1400 °C/30 h). The Nb3Si phase has transformed into Nbss and α-Nb5Si3 with the OR have been determined as {100}Nbss//{100}α and{111}Nbss//{111}α in the heat-treated 4Mo-3Zr alloy. When Mo content increase to 8at.%, a part of γ-Nb5Si3 phase also transformed into the α-Nb5Si3 phase with the OR have been determined as {11 2 ¯ 0}γ//{110}α and {10 1 ¯ 0}γ//{111}α after heat treatment. Among the as-deposited alloys, the 4Mo-6Zr alloy has the highest fracture toughness KQ with the lowest hardness. The average KQ of 4Mo-6Zr and 8Mo-6Zr alloys increased by 28% and 30% after the heat treatment, and reached 13.61 and 11.43 MPa•m1/2, respectively. The hardness of Nb-22Ti-15Si-xMo-yZr alloys is significantly decreased after the heat treatment.

Laser solid forming (LSF) technology can be used to rapidly manufacture and repair high-strength steel parts with superior performance, but the value of the heat input during operation is difficult to quantify, which has a substantial impact on the microstructure and mechanical properties of the parts. A promising method to improve the forming efficiency and quality of LSFed parts is to accurately control the heat input and explore its relationship with the microstructure and mechanical properties. To remove the interference of other variables from the experiment, the dimensionless heat input Q* was introduced. The Q* values were designed in advance to calculate the experimental parameters used to perform the LSF experiment. The microstructure was observed at different regions of the sample, and its mechanical properties were analyzed. From the results, the following conclusions were drawn. The Q* value was directly related to the cooling rate and heat accumulation in the top structure, leading to the formation of different microstructures; it also modified the original structure at the bottom, affecting the subsequent thermal cycle and indirectly changing the tempered martensite morphology. The heat input also affected the mechanical properties of the sample. The hardness of the stable zone decreased with increasing Q* value, and the lowest value was 190 HV. Similarly, the tensile strength and yield strength of the LSFed samples decreased considerably with increasing Q* value, and the lowest values were 735 and 604 MPa, respectively. Only the elongation and reduction in the area increased after a slight decrease. The Q* value had a significant effect on heat treatment. When Q* = 2.9, the increase in tensile strength and yield strength after heat treatment was the largest (29% and 44%, respectively).

Near-equiaxed β grain was achieved in the near-α Ti60 (Ti-5.7Al-4.0Sn-3.5Zr-0.4Mo-0.4Si-0.4Nb-1.0Ta-0.05C) titanium alloy via laser directed energy deposition (LDED). The microstructural evolution along the building direction and the room-temperature tensile properties along the horizontal and vertical directions (building direction) were systematically studied through SEM and OM. EBSD and XRD were utilized to accurately demonstrate the texture of the α and β phases. The results showed that the α phase presented a low texture intensity, which was ascribed to the weak textured β grain with near-equiaxed morphology, since there are Burgers orientation relationships during the β→α transition. In addition, numerical simulation, combined with the CET curve of Ti60 alloy considering the effect of multi-composition, was utilized to elucidate the formation mechanism of the near-equiaxed β grains. Furthermore, according to the solidification theory, we proposed that the solidification temperature range Δ T f was more accurate than the growth restriction factor Q in predicting the formation tendency of equiaxed β grain in different titanium alloys. Tensile results showed that the horizontal and vertical samples had similar strength, while the former exhibited larger elongation than the latter. The effect of the near-equiaxed β grain and the internal α phase on mechanical properties were revealed at last.

Laser powder bed fusion (L-PBF) of Sc/Zr-modified Al-based alloys has recently become a promising method for developing a new generation of high-performance Al alloys. To clarify the modification roles of Sc/Zr elements, an Al–4.66Mg–0.48Mn–0.72Sc–0.33Zr (wt.%) alloy was processed using L-PBF. The effect of the local solidification condition of the molten pool on the precipitation behavior of primary Al3(Sc,Zr) was analyzed based on time-dependent nucleation theory. It was found that primary Al3(Sc,Zr) inevitably precipitated at the fusion boundary, while its precipitation could be effectively suppressed in the inner region of the molten pool. This subsequently induced the formation of a heterogeneous α-Al matrix. After direct aging, the heredity of solidification microstructure introduced heterogeneous secondary Al3(Sc,Zr) precipitates within α-Al matrix. Owing to the inverse relationship between grain boundary strengthening and precipitation strengthening, the direct-aged sample with dual heterogeneous structures exhibited reduced mechanical heterogeneity, resulting in lowered hetero-deformation-induced hardening. The low strain-hardening capability in the direct-aged sample promoted necking instability while inducing a large Luders elongation, which effectively improved the tensile ductility.

Although a variety of processing routes were developed to in-situ manipulate microstructure for fabricating high-performance Ti–6Al–4V alloy by directed energy deposition (DED), the in-situ microstructural control ability has been limited and lead to a narrowed mechanical property control range. This work proved the microstructural correlation between β-grains and α-laths resulting from the unique thermal characteristics of DED for the first time and solved such a dilemma through synchronous induction heating assisted laser deposition (SILD) technology. The results confirmed that the laser energy and inductive energy have a different effect on the solidification and solid phase transformation conditions. By adjusting the laser-induction parameters, the microstructural correlation can be tuned; the β-grains and α-laths can be controlled relatively separately, thereby significantly enhancing the ductility of as-deposited sample (elongation from 14.2% to 20.1%). Furthermore, the mechanical properties of the tuned microstructures are even comparable to that of DED Ti–6Al–4V with post heat treatment, which indicates that the potential of SILD to be a one-step manufacturing process to fabricate high performance components without post heat treatment. Furthermore, the tensile testing results of the tuned microstructures indicate that α-lath size is more influential on the mechanical properties than the β-grain size due to its stronger hindering effect on the slipping of dislocations. This work promotes the understanding of the microstructural formation mechanism in DED titanium alloy and proves that the combination of synchronous induction and laser can expand the ability to control the microstructure and properties of multi-layer deposition.

Purpose This study aims to develop a data fusion method for powder-bed fusion (PBF) process monitoring based on process image information. The data fusion method can help improve process condition identification performance, which can provide guidance for further PBF process monitoring and control system development. Design/methodology/approach Design of reliable process monitoring systems is an essential approach to solve PBF built quality. A data fusion framework based on support vector machine (SVM), convolutional neural network (CNN) and Dempster-Shafer (D-S) evidence theory are proposed in the study. The process images which include the information of melt pool, plume and spatters were acquired by a high-speed camera. The features were extracted based on an appropriate image processing method. The three feature vectors corresponding to the three objects, respectively, were used as the inputs of SVM classifiers for process condition identification. Moreover, raw images were also used as the input of a CNN classifier for process condition identification. Then, the information fusion of the three SVM classifiers and the CNN classifier by an improved D-S evidence theory was studied. Findings The results demonstrate that the sensitivity of information sources is different for different condition identification. The feature fusion based on D-S evidence theory can improve the classification performance, with feature fusion and classifier fusion, the accuracy of condition identification is improved more than 20%. Originality/value An improved D-S evidence theory is proposed for PBF process data fusion monitoring, which is promising for the development of reliable PBF process monitoring systems.

p-Benzoquinone (BQ) is a promising candidate for next-generation sodium-ion batteries (SIBs) because of its high theoretical specific capacity, good reaction reversibility, and high resource availability. However, practical application of BQ faces many challenges, such as a low discharge plateau (∼2.7 V) as cathode material or a high discharge plateau as anode material compared with inorganic materials for SIBs and high solubility in organic electrolytes, resulting in low power and energy densities. Here, tetrahydroxybenzoquinone tetrasodium salt (Na4C6O6) is synthesized through a simple neutralization reaction at low temperatures. The four −ONa electron-donating groups introduced on the structure of BQ greatly lower the discharge plateau by over 1.4 V from ∼2.70 V to ∼1.26 V, which can change BQ from cathode to anode material for SIBs. At the same time, the addition of four −ONa hydrophilic groups inhibits the dissolution of BQ in the organic electrolyte to a certain extent. As a result, Na4C6O6 as the anode displays a moderate discharge capacity and cycling performance at an average work voltage of ∼1.26 V versus Na/Na+. When evaluated as a Na-ion full cell (NIFC), a Na3V2(PO4)3 ‖ Na4C6O6 NIFC reveals a moderate discharge capacity and an average discharge plateau of ∼1.4 V. This research offers a new molecular structure design strategy for reducing the discharge plateau and simultaneously restraining the dissolution of organic electrode materials.

A new model for predicting elastic flexural wave band gaps in periodic composite plate structures containing interconnected, star-shaped, transversely isotropic, magneto-electro-elastic (MEE) inclusions is developed using a microstructure-dependent Mindlin plate model. The Floquet–Bloch theorem and the plane wave expansion method for periodic media are employed to solve the non-classical wave equations and to determine the band gaps incorporating the microstructure effect. The current non-classical model recovers its classical elasticity-based counterpart as a special case if the microstructure effect is suppressed. A parametric study is performed to demonstrate the newly developed model. The numerical results of the study show that the microstructure effect on band gaps is large when the plate is very thin. In addition, the unit cell edge length, inclusion geometry and MEE coupling have significant effects on band gap sizes, and large band gaps can be generated by tailoring the controlling parameters.

Electrochemical CO2 reduction provides a promising strategy to product value-added fuels and chemical feedstocks. However, it remains a grand challenge to further reduce the overpotentials and increase current density for large-scale applications. Here, spontaneously Sn doped Bi/BiOx nanowires (denoted as Bi/Bi(Sn)Ox NWs) with a core-shell structure were synthesized by an electrochemical dealloying strategy. The Bi/Bi(Sn)Ox NWs exhibit impressive formate selectivity over 92% from -0.5 to -0.9 V versus reversible hydrogen electrode (RHE) and achieve a current density of 301.4 mA cm-2 at -1.0 V vs RHE. In-situ Raman spectroscopy and theoretical calculations reveal that the introduction of Sn atoms into BiOx species can promote the stabilization of the *OCHO intermediate on the Bi(Sn)Ox surface and suppress the competitive H2/CO production. This work provides effective in situ construction of the metal/metal oxide hybrid composites with heteroatom doping and new insights in promoting electrochemical CO2 conversion into formate for practical applications.

The failure of transpassive films on transition metal alloys was investigated. The results show that the failure of the transpassive film on 3D printing nickel-based superalloy in flowing NaNO3 solution is dominated by self-induced cracking of the film on niobium-segregated phases and the erosion-induced degradation on the film assisted by cation vacancy condensation at the metal/barrier layer interface. Secondary passivation induces the formation of a transpassive film, the nature of which has been debated for decades. The findings are consistent with a bi-layer structure comprising a point-defective barrier layer that grows into the substrate alloy and a precipitated outer layer.

Peritectic solidification has attracted increasing attention as a lot of important binary alloys, such as Fe–Ni, Zn–Cu, Fe–C and Ti–Al, exhibit peritectic reaction during solidification. In order to investigate the solidification behavior of Zn-rich Zn–Cu peritectic alloy containing nominally up to 7.8 wt.% Cu, a series of laser surface remelting experiments were performed. With the increase in growth velocity, Zn–Cu alloys with Cu content below 3.0wt.% showed an evolutional sequence from low-velocity η planar interface → lamellar structures → η shallow cells and finally to high-velocity η planar interface. The Zn-4.0 wt.%Cu alloy showed a similar transitional sequence except that irregular η cells appeared when low-velocity planar interface became unstable. In contrast, e cell/dendrite was the typical microstructure of the Zn-7.8 wt.% Cu alloy within the whole scanning velocity range. Based on the maximum interface temperature criterion, a eutectic growth model under rapid solidification conditions (TMK model) and a self-consistent numerical model for the cellular and dendrite growth were applied to establish a phase and microstructure pattern selection map, which drew a clear whole picture of the relationship between phase/microstructure and solidification conditions of this series of alloys. Regarding the microstructure feature, our investigation revealed the range of the solidification velocity and chemical composition of lamellar structures as dominant microstructure and their lamellar spacing displayed a considerable range of the average value as a function of growth velocity. The relationship between the lamellar spacing and the growth velocity was further analyzed by using the TMK eutectic model, and the results showed the same overall trend as the experimental results. A phase and microstructure pattern selection map of Zn-rich Zn–Cu peritectic alloys. Regression analysis of the average spacing of lamellar structures.

Electronic doping of organic semiconductors is essential for their usage in highly efficient optoelectronic devices. Although molecular and metal complex-based dopants have already enabled significant progress of devices based on organic semiconductors, there remains a need for clean, efficient and low-cost dopants if a widespread transition towards larger-area organic electronic devices is to occur. Here we report dimethyl sulfoxide adducts as p-dopants that fulfil these conditions for a range of organic semiconductors. These adduct-based dopants are compatible with both solution and vapour-phase processing. We explore the doping mechanism and use the knowledge we gain to 'decouple' the dopants from the choice of counterion. We demonstrate that asymmetric p-doping is possible using solution processing routes, and demonstrate its use in metal halide perovskite solar cells, organic thin-film transistors and organic light-emitting diodes, which showcases the versatility of this doping approach.

During COVID-19, with a heavy sprayer filled with disinfectant, the risk of infection for epidemic prevention personnel has been increased by long-term environmental disinfection. In order to reduce the burden and save energy of human, this letter proposed a Wheel-Legged Robotic Limb (WRL) for the carriers. The mass of WRL is only 1.77 kg. The WRL has one rigid robotic limb located below the sprayer, which can provide active supporting force for the sprayer. The WRL adopts force closed-loop control method to ensure the system provide an expected supporting force. The system performance was evaluated including standing and walking at 5 km/h, under three experimental conditions included: 1) with a sprayer, 19.41 kg (SPRAYER), 2) with the powered WRL, 22.18 kg (WRL_ON), and 3) with the unpowered WRL, 22.18 kg (WRL_OFF). When the supporting force is set as 80 N, the experimental results show that the WRL_ON condition has reduced the vertical load force on the human, the vertical ground reaction force of human feet, and the metabolic power by 41.28%, 8.03%, and 17.46% during standing, and also reduced by 32.29%, 8.08% and 18.92% during walking, compared to SPRAYERcondition, respectively.

The control of grain morphology is important in laser additive manufacturing (LAM), as grain morphology further affects the hot cracking resistance, anisotropy, and strength–ductility synergy of materials. To develop a solidification-control solution and achieve columnar-to-equiaxed transition (CET) in Al-based alloys during LAM, Sc-and-Zr-modified Al-Mg alloys were processed via directed energy deposition (DED). CET was achieved by introducing high potent primary Al3(Sc,Zr) nucleation sites ahead of the solidification interface. Furthermore, the relationship between the solidification control parameters and precipitation behavior of primary Al3(Sc,Zr) nucleation sites was established using the time-dependent nucleation theory. Then, the CET was studied according to the Hunt criterion. The results indicated that coarse columnar grain structure was still obtained at the inner region of the molten pool at low Sc/Zr contents owing to the effective suppression of the precipitation of the primary Al3(Sc,Zr) nucleation sites via rapid solidification during DED. In addition, the relatively low melt temperature at the fusion boundary unavoidably promoted the precipitation of primary Al3(Sc,Zr) nucleation sites, which resulted in a fine equiaxed grains band at the edge of the molten pool. As the Sc/Zr content increased, the solidification cooling rate was not sufficient to suppress the precipitation of the primary Al3(Sc,Zr) nucleation sites, and a fully equiaxed grain structure was obtained. Furthermore, the effect of the layer-by-layer manufacturing process on the subsequent precipitation strengthening of secondary Al3(Sc,Zr) precipitates was discussed. Both the remelting and subsequent aging during thermal cycling should be considered to achieve greater precipitation strengthening.

Wearable thermoelectric generators as renewable energy conversion technologies have witnessed rapid development in the past decade. Herein, we design a nanowire (NW) film wavy structure which possesses an excellent temperature gradient ratio for stretchable thermoelectric generators. Taking advantage of the photothermal effect of Te NWs as the hot side and p-n NWs heterofilms (n-type Ag

A non-classical model for circular cylindrical thin shells is developed by using a modified couple stress theory and a surface elasticity theory. The equations of motion and boundary conditions are simultaneously obtained by a variational formulation based on Hamilton’s principle, which provides a unified treatment of the microstructure and surface energy effects. The new non-classical shell model contains one material length scale parameter to capture the microstructure effect and three surface elastic constants to describe the surface energy effect. The current model includes the shell models considering the microstructure effect only or the surface energy effect alone as special cases. Also, the newly developed shell model reduces to the classical circular cylindrical Love–Kirchhoff thin shell model when both the microstructure and surface energy effects are suppressed. In addition, it recovers the non-classical model for Kirchhoff plates incorporating the microstructure and surface energy effects when the shell radius tends to infinity. To illustrate the new model, the static bending and free vibration problems of a simply supported closed circular cylindrical shell and of an open circular cylindrical shell with free edge boundary conditions are analytically solved by directly applying the model. For the static bending problem in each case, the numerical results show that the shell deflection predicted by the current model is smaller than that predicted by the classical model, and the difference is significant when the shell is very thin but diminishes as the shell thickness increases. For the free vibration problem in each case, it is found that the natural frequency predicted by the new model is higher than that predicted by its classical counterpart, and the difference is large only for very thin shells.

In this study, non-toxic in-situ β phases of reinforced Ti/Zr-based bulk metallic glass matrix composites (BMGCs) of (Ti0.65Zr0.35)100-xCux (x = 5, 10, 15 at.%) are fabricated via selective laser melting. The effect of Cu content on phase formation, microstructure, and mechanical properties is investigated. The average volume fraction and width of the β phase decreases with increasing Cu content, while a more amorphous phase and the (Ti, Zr)2Cu phase forms. In the center zone of the molten pool, the β phase grows in the direction of the temperature gradient, and the amorphous phase distributes among the β phases. This occurs using: sphere morphology (for x = 5), a more continuous elongated sphere and network morphology (for x = 10), and network morphology (for x = 15), respectively. In the edge zone of the molten pool, due to the smaller cooling rate and the existence of a partially molten zone, the β phase becomes coarser, and an amorphous phase forms for more continuous networks. Furthermore, the hardness improves significantly with increasing Cu content. No crack is found for x = 5. Although the average volume fraction of the β phase for x = 5 is about 90 %, the compression yield strength is 1386 ± 64 MPa, reaching to an average level of conventionally fabricated counterparts, due to finer microstructure, and twinning and martensitic transformation of the β phase.

A new microstructure-dependent non-classical model for Kirchhoff plates is developed by using a reformulated strain gradient elasticity theory that incorporates both the strain gradient and couple ...

A shear-lag model is developed for discontinuous fiber-reinforced composites with a membrane-type imperfect interface, across which the displacement vector is continuous but the traction vector suffers a jump that is governed by the generalized Young–Laplace equation. Closed-form expressions are obtained for the stress fields in both the fiber-reinforced region and the pure matrix regions and for the shear stress on the interface from both the fiber and matrix sides. To illustrate the newly developed analytical model, a numerical analysis is provided by directly using the general formulas derived. The numerical results reveal that the fiber aspect ratio and the interface parameter can both have significant effects on the stress distributions in the composite.

A new model for anisotropic magneto-electro-elastic Mindlin plates is developed by using an extended modified couple stress theory. The equations of motion and complete boundary conditions are simultaneously obtained by a variational formulation based on Hamilton’s principle. The new anisotropic magneto-electro-elastic plate model includes the models for orthotropic and transversely isotropic magneto-electro-elastic Mindlin plates and the model for isotropic Mindlin plates, all incorporating the microstructure effect, as special cases. To illustrate the new model, the static bending and free vibration problems of a simply supported transversely isotropic magneto-electro-elastic plate are analytically solved by directly applying the general formulas derived. For the static bending problem, the numerical results reveal that the deflection, rotation, electric potential, and magnetic potential of the simply supported plate predicted by the current non-classical model are always smaller than those predicted by the classical elasticity-based model, and the differences are significant when the plate thickness is very small but is diminishing as the thickness increases. For the free vibration problem, it is found that the natural frequency predicted by the new plate model is higher than that predicted by the classical model, and the difference is quite large for very thin plates.

Roma Plastilina (RP) # 1 clay has been used as a backing material in ballistic testing of body armor. Column-drop tests are conducted to assess the suitability of RP # 1 clay for ballistic tests. I...