Design Method Research Articles

New Swedish Design Method for Concrete Pavements

A new concrete pavement design method is currently introduced in Sweden. It consists of two parts: (i) computations of subgrade and base distresses and (ii) computations of concrete pavement distresses. To eliminate the difference between concrete and asphalt pavement design, the first part is carried out with equal requirements, in the same manner, and with the very same computer program. The computer run also provides a coefficient of subgrade reaction that is used as input in the second part. For this part, the American FE program ISLAB2000 is used to compute stresses – both traffic and thermal stresses, simultaneously – in various locations of the concrete pavement slab. Contrary to previous Swedish tradition, both bottom-up and top-down cracking are considered in the analysis of the computations. For the pavement designer, the division into two parts will not be visible. She will use the same user-friendly computer program (that previously has only been used for flexible pavement design) for both pavement alternatives. It is the authors’ hope that the selection of pavement solution for a certain case will be dependent solely on technical and economical factors and not on tradition and intensive advertising. The new design method includes a novelty concerning safety philosophy. The safety margin should be obvious and transparent and determined by the client in co-operation with the designer by selecting an appropriate safety class that is dependent on the economical consequences of a pavement failure but independent of material in the wear layer.

MIXTURE RATIO DESIGN METHOD FOR POROUS CONCRETE PERMEABLE BASE

As a new kind of material for permeable base, mixture ratio design of porous concrete should ensure both the porosity and the mechanical strength. Based on Talbol Formula and foreign experiences, four kinds of gradation of porous concrete are designed and effective particle size and uniform coefficient are taken as the effective descriptive targets of aggregate gradation. Three factors of cement dosage, water cement ratio and aggregate gradation are considered in an orthogonality test with four levels adopted in every factor. Through variance analysis of the tests results, it can be drawn that when confidence probability is 95%, the factors that evidently affect 7d compressive strength are gradation and cement aggregate ratio, and the factors evidently affect effective porosity are gradation, cement aggregate ratio and water cement ratio. While when confidence probability is 90%, gradation, cement dose and water cement ratio all have evident influence on 7d compressive strength and effective porosity. Based on the test results, a series of regression relationships of 7d compressive strength and effective porosity of porous concrete are derived. Finally, the empirical equation method of mixture ratio design for porous concrete is proposed.

Load Transfer through Aggregate Interlock: Crack Width, Aggregate Type and Performance

It is well known that performance of plain jointed concrete pavements depends on aggregate interlock to transfer load from the one slab to the next. In order to quantify the relative contribution of crack width and the strength of the aggregate to the long-term performance of a plain jointed pavement, experimental sections of road were built using different aggregates types. These sections were subsequently loaded to failure using the Heavy Vehicle Simulator (HVS). Some typical sections of interstate-type highways, which had been under traffic for between ten and twenty years were also investigated using FWD testing and determination of changes in crack width with changes in temperature. Detailed asbuilt information including concrete mix characteristics was available for all these sections. This paper discusses the prediction of crack width using the RILEM model which predicts early age shrinkage. The model was modified to include the effects of aggregate type, environmental conditions and age. The change in load transfer at the joints and cracks, as indicated by relative vertical movement under dynamic loading as a result of temperature variation and humidity, is reported on. It was found that a change in load transfer occurred under increased loading and that this could be related to the crushing characteristics of the coarse aggregate. This paper presents the final outcome of the study in terms of theoretically based equations that were adjusted using regression techniques to fit the field experience. These equations have now been incorporated into a mechanisticallybased design method for concrete pavements, cncPave.

3-D Design Method of the Gear Cutting Tool Profile Based on Reverse Engineering

3-D Design Method of the Gear Cutting Tool Profile Based on Reverse Engineering

Performance of a Thin CRCP Inlay Designed for a Five-Year Life: a Case Study

The steep uphill section of an interstate highway had experienced considerable damage in the form of serious rutting due to slow-moving heavy vehicles. The asphalt pavement had had to be rehabilitated every 4 years and a decision was made to mill and replace the top 180mm of the slow lane with a CRCP inlay. The inlay design was based on an anticipated 6 million equivalent 80 kN axles over five years and it was envisaged that a concrete overlay would be placed over the full width of the road at the end of this period. However, at the end of six years only approximately 0.25% of the area of the inlay had shown serious distress. It was decided to determine the remaining structural life of the pavement with a view to repairing failed areas permanently, rather than temporarily, if the remaining structural life was found to be significant. This paper describes the testing of behaviour and performance on a relatively highly cracked section of the inlay using the Heavy Vehicle Simulator (HVS). Although the test section had narrowly spaced transverse cracking prior to testing, no punch-outs could be created using the HVS. A detailed survey of the 26 lane km of inlay showed that failure did not necessarily occur at closely spaced cracks, but was more associated with edge loading, loss of slab support and poor quality concrete. It also became very clear that a high variation in concrete characteristics (and in particular concrete strength) resulted in a high risk of structural failure. The results were translated into transfer functions that have been included in cncPave, a mechanistically-based design method for concrete pavements developed for South African conditions.

Adaptive Controller Design for Improving Helicopter Flying Qualities

A comprehensive flight control law design method based on adaptive control is presented in this paper. The proposed method consists of three basic modules—model decoupling, online system identification and adaptive pole placement. The model decoupling module decouples the helicopter flight dynamics model based on dynamic inversion technique. This procedure helps to reduce the difficulties in online system identification and adaptive controller design. In online system identification module, a recursive extended least squares algorithm is established to identify the augmented linear flight dynamics model which is composed of helicopter model and unideal noise model. The helicopter model parameters and the noise parameters are identified simultaneously which improves the identification accuracy as well as robustness. Pole placement is implemented in the last module, and an optimization method is developed to help selecting ideal poles. The adaptive rule in this step is designed based on eigenvalue analysis of the model to remove all unnecessary oscillations of the control parameters. An adaptive controller is designed according to the developed method for the UH-60A helicopter based on a nonlinear simulation program. Typical response types are also implemented. The simulation results show that the designed adaptive controller has high performance as well as robustness in both hover and forward flight.

The Optimization of the Rear Guide Vane of a Bulb Tubular Pump Based on Orthogonal Tests

Bulb tubular pumps have been widely used in hydraulic engineering because of their compact structure, easy maintenance, high adaptability, and other characteristics. In this paper, the performance optimization of the bulb tubular pump in the South-to-North water diversion project is studied, as well as the influence of the design of the rear guide vane structure on the hydraulic efficiency of the pump. This study takes a certain type of bulb tubular pump as its research object, optimizing the rear guide vane. Firstly, the accuracy of the numerical simulation method is verified using grid convergence analysis and model experimentation. The orthogonal experimental design method is used to optimize the design, and the range analysis results show that the blade wrap angle has the most significant influence on the hydraulic efficiency and head. Finally, the optimization results under a 0° impeller setting angle were verified by numerical analysis, and the hydraulic efficiency of the optimized pump was increased by 0.7%, 0.88%, and 1.1% under low flow, design flow, and high flow, respectively. By introducing entropy generation theory for inflow analysis, the reduction in energy loss in the pump is proven, thus verifying the effectiveness of the optimization. Through the optimization, the separation fluid phenomenon on the guide vane surface is improved, the vortex scale is reduced, and the flow field in the pump is improved to a certain extent.

Fuzzy self-tuning fractional order PD permanent magnet synchronous motor speed control based on torque compensation

The permanent magnet synchronous motor control system is characterized by its nonlinear and strongly coupled complexity, presenting significant challenges for control performance optimization. To address these challenges, a Fuzzy adaptive fractional order control strategy based on torque observation compensation is proposed. The parameters of the fractional order controller are optimized real time using fuzzy logic reasoning, in order to enhance the speed of parameters tuning, a graphical design method of the fractional order controller parameters based on frequency domain performance indicators is proposed to obtain the initial values of the fuzzy adaptive fractional order controller parameters graphically and intuitively. Furthermore, a load torque observer is designed to improve the anti interference capability of the system by proportionally converting the observed load torque into compensation current in equal proportion. Simulation and experimental results validate that the proposed strategy demonstrates superior dynamic and static performance, as well as robustness.

Development of Nutraceutical and Nutritional Design Method for Liposomal Curcumin and Vitamin C Using Microstructural and Elemental Analysis

Development of Nutraceutical and Nutritional Design Method for Liposomal Curcumin and Vitamin C Using Microstructural and Elemental Analysis

Three-Dimensional Multi-Morphology TPMS-Based Microchannel Design Method for Conformal Cooling in Injection Molding

Abstract Triply periodic minimal surface (TPMS) possesses diverse morphological characteristics, such as pore sizes, porosity, and structural types. Integrating TPMS-based microchannels into micro-cellular cooling structures is advantageous for designing and controlling fluid characteristics within mold cooling channels. However, it is still difficult to design multi-morphology TPMS-based cooling microchannels that conform to the external shapes of injection molds. This work proposes a 3D multi-morphology TPMS-based design method that transforms 3D constraints into a combination of 2D constraints. First, a beta growth algorithm based on closed-loop constraints is proposed to transition different morphologies smoothly on the plane. Subsequently, a transition optimization algorithm along the normal direction of the plane is introduced to smoothly transition multi-morphology TPMS-based microchannels in all directions. With this layered approach, multi-morphology microchannels can be obtained with first-order geometric continuity under complex shape constraints. Finally, several TPMS-based conformal cooling structures are designed for an automotive hood cover. The results of finite element simulations show that the cooling structures generated by the proposed method have a better cooling effect than the conformal channels. It can be concluded that multi-morphology TPMS-based structures perform better by contrast with conformal channels as the average temperature of the cooling surface decreases by 8.48 K, and the standard deviation of temperature distribution decreases by 24.65%.

Integrated Sensing and Communication Target Detection Framework and Waveform Design Method Based on Information Theory

Target detection is a core function of integrated sensing and communication (ISAC) systems. The traditional likelihood ratio test (LRT) target detection algorithm performs inadequately under low signal-to-noise ratio (SNR) conditions, and the performance of mainstream orthogonal frequency division multiplexing (OFDM) waveforms declines sharply in high-speed scenarios. To address these issues, an information-theory-based orthogonal time frequency space (OTFS)-ISAC target detection processing framework is proposed. This framework adopts the OTFS waveform as its fundamental signal. The target detection is implemented through a relative entropy test (RET) comparing echo signals against target presence/absence hypotheses. Furthermore, to enhance the system’s target detection capability, the iterative OTFS-ISAC waveform design (I-OTFS-WD) method which maximizes the relative entropy is proposed. This method utilizes the minorization-maximization (MM) algorithm framework and semidefinite relaxation (SDR) technique to transform the non-convex optimization problem into an iterative convex optimization problem for resolution. The simulation results demonstrate that, under sufficient sample conditions, the RET algorithm achieves a 9.12-fold performance improvement over LRT in low-SNR scenarios; additionally, the optimized waveform reduces the sample requirements of the RET algorithm by 40%, further enhancing the target detection capability of the OTFS-ISAC system.

A novel active switchable multi-channel waveguide based on the Bragg scattering mechanism and the force-magnetic coupling effect

PurposeThis study aims to propose a novel acoustic metamaterial waveguide with active switchable channels by changing the magnetic field strength.Design/methodology/approachBased on the Bragg scattering mechanism and the force-magnetic coupling effect of magnetorheological elastomer (MRE), an acoustic metamaterial waveguide structure containing lead scatterers and an MRE/rubber matrix is constructed. By changing the external magnetic field strength, the bandgap of the acoustic metamaterial can be adjusted, and then the channels of the proposed acoustic metamaterial waveguide can be actively switched. The bandgap ranges of acoustic metamaterials containing scatterers with different sizes are different and by designing the size of the scatterers, an acoustic metamaterial waveguide can be formed. The design and control method of this study will be useful for the design of waveguides and active control of bandgaps.FindingsThe proposed switchable multi-channel waveguide and active control method can effectively control the elastic wave propagation, and the opening and closing of the channel are achieved.Practical implicationsThis study provides a new control method for waveguides and expands the application range of MRE. The proposed design concept of adjustable waveguides can be extended for the design of waveguides, metamaterials and vibration reduction structures.Originality/valueThis article proposes a waveguide structure controlled by an external magnetic field in a non-contact manner based on the principle of Bragg scattering and the force-magnetic coupling effect. The model is established, and its feasibility is demonstrated through numerical simulations.

An Optimized Design Method for Magnetometer Targeting High-Precision Measurement of Quasi-Periodic Magnetic Field Signal

An Optimized Design Method for Magnetometer Targeting High-Precision Measurement of Quasi-Periodic Magnetic Field Signal

Design of a high transmission illumination optics for anamorphic EUV lithography optics using deep reinforcement learning

The design of the illumination optics for high numerical aperture (NA) anamorphic extreme ultraviolet (EUV) projection optics is a critical challenge to EUV lithography in advanced technology node. However, the EUV illumination optics design using conventional methods have flaws in illumination efficiency and illumination uniformity due to the limitations of relay configuration and matching method that can only consider one factor affecting illumination uniformity. One-mirror configuration can improve illumination efficiency by reducing the number of mirrors. Deep reinforcement learning (RL) can solve the limitations by considering multiple factors simultaneously. In this paper, a design method for a high transmission relay system and a matching method for double facets using deep RL are proposed to design NA 0.55 anamorphic EUV illumination optics. The one-mirror relay system is designed by first calculating its coaxial spherical initial configuration using matrix optics; then the one off-axis relay mirror, which is tilted and decentered to eliminate ray obscuration, is fitted into a conic surface. To satisfy the requirements of multiple factors that affect illumination uniformity, the assignment relationships between the field facets and the pupil facets are determined using deep RL under a certain illumination mode. Simulation results show that the illumination efficiency is 26.24%, and the illumination uniformity can reach 99% on the mask under different illumination modes.

Theoretical analysis, simulation, and field experiment for vibration mitigation of suspender cables/hangers using the four‐wire pendulum tuned mass damper

AbstractSuspender cables/hangers occupy a crucial role during the whole service life of suspension bridges/arch bridges/space structures, and their long‐term repeated vibration under corrosion and high‐stress service state will cause fatigue damage and even induce fatigue failure. To mitigate the vibration of the vertical suspender cables/hangers, a four‐wire pendulum tuned mass damper (FWPTMD) is proposed. It mainly consists of the cross bracket, four pendulum ropes, the moving mass, and four universal rotating ball hinges that can rotate in any direction and provide damping. A suspender cable in a real suspension bridge is selected as the research object. First, the design procedure and effect of the modal mass ratio are provided; the optimization design method for parameters of optimal frequency ratio and optimal damping ratio is investigated in detail. Second, simulations are conducted to illustrate its feasibility, and results show excellent vibration mitigation effect. Third, the optimal FWPTMD is designed and fabricated; its performance is further validated by field experiments, and the results are very close to those in simulation. The FWPTMD has the advantages of simple structural form, convenient installation, low cost, easy tuning, easy maintenance, and so forth. Therefore, it can play an obvious vibration mitigation role in the life‐cycle of the suspender cable/hanger, and it has a positive meaning to retard fatigue damage, extend the service life, and assure traffic safety under extreme weather.

Inverse-designed all-silicon nanowire array cavities

We designed silicon nanowire array cavities with high optical confinement (Γ) in the central nanowire and a high quality factor (Q) through an inverse design method that maximizes Γ×Q. Moreover, we fabricated an inversely designed cavity with inline input and output waveguides, which is a new configuration for such cavities. The experimental Q exceeded 50,000, which was consistent with a simulation. The cavity exhibited the thermal nonlinearity effect and optical bistability, which indicate that our cavity strongly confines the light in the nanowires.

TIG welding process on IS 2062A steel of 5 mm plate, utilizing a 2.5 mm diameter tungsten solid wire as electrode along with direct current straight polarity and argon inert gas was employed for shielding purpose

The quality as well as efficient welding is crucial to fulfil the consumer satisfaction and getting returns from production, which is mostly depends on weld bead properties for any welding process, which is influence by the selected welding method and its process variables. So, the significant efforts are to choose the appropriate welding process in addition the process parameters as well as their level. In an atmosphere of welding different technique have been developed in last few decades, the demand of Gas Tungsten arc welding (GTAW) or Tungsten inert gas welding (TIG) has been increasing day by day owing to it has potential to fabricate multiple metallic materials (similar/dissimilar), quality joint, smooth modification for industrialization, higher efficiency, and low capital cost. However, published literature regarding research on TIG welding of IS 2062A steel is notably scarce. Detailed discussions on the optimization techniques exploring the impact of process parameters such as welding current, traversing speed, and gas flow rate on both weld quality and bead geometry in TIG welding of mild steel are conspicuously absent in prior works. So it is very crucial for quality joint to applied process optimization on TIG Welding parameters. The study focused on tungsten inert gas welding process on 5 mm thick plate of IS 2062A steel, utilizing a 2.5 mm diameter tungsten solid wire as electrode along with direct current straight polarity and argon inert gas was employed for shielding purpose. To streamline experimentation, a multi-response optimization technique was employed, using Taguchi's L16 experimental design method. Among several welding parameters, the significant parameters like current (I), traversing speed (S), and gas flow rate (Gf) were considered, others parameters were kept constant. The study measured various aspects of bead properties, including penetration, bead width, and depth of HAZ, along with HAZ hardness. The optimized parameter settings, derived from the signal-to-noise (S/N) ratio, has been validated as improved the weldment properties along with possess highest grey relation grade, which highlighting the effectiveness of the Grey-based Taguchi method in enhancing joints properties as product quality together with efficiency in manufacturing. Quantitative assessment via the analysis of variance method was conducted to determine the relative significance of each variable on the overall output characteristics of the weldment.

Assessment of Sensory and Nutritional Attributes of Finger Millet-based Traditional Food Products of Assam, India

Background: Millet based diets contain multiple health promoting components and considered as climate-resilient course grain cereals. The United Nations designated 2023 as the 'International Year of Millets' to spotlight the resilience and health benefits of these climate-adaptable crops. In line with this, the Shree Anna (Millet) Gram Yojana was initiated to promote millet production and consumption, aiming to combat malnutrition. An essential aspect of this initiative is the substitution of millet for rice in traditional recipes, a strategy for sustainable food and nutritional security. This study, conducted by the AICRP on Women in Agriculture at Assam Agricultural University, Jorhat, focused on utilizing Finger Millet (Eleusine coracana) in Assam's traditional food products—Burbhuria pitha, Pat pitha, Tel pitha, and Mithoi. Aim: Evaluating the quality of these millet-based food products in terms of organoleptic properties and nutritional composition. Methodology: A nine-point hedonic scale was used to conduct sensory evaluations by ten trained and semi-trained panelists from the Department of Food Science and Nutrition, and nutritional composition was examined. ICAR WASP software was utilized to analyze the data using the Completely Randomized Design method. Results: Results indicated that Finger Millet substituted for rice in traditional food products of Assam received higher acceptability scores and exhibited improved nutritional profiles compared to control products. Conclusion: This study underscores the potential of value-added products with Finger Millet to enhance flavour, texture, taste, and nutritional value of traditional foods, offering benefits to the populace of Assam.

Reverse design of broadband sound absorption structure based on deep learning method

This research presents a method based on deep learning for the reverse design of sound-absorbing structures. Traditional methods require time-consuming individual numerical simulations followed by cumbersome calculations, whereas the deep learning design method significantly simplifies the design process, achieving efficient and rapid design objectives. By utilizing deep neural networks, a mapping relationship between structural parameters and the sound absorption coefficient curve is established. The forward network predicts the sound absorption coefficient curve, while the reverse network enables the on-demand design of structural parameters for broadband high sound absorption. During the design process, a mean squared error (MSE) below 0.0001 is achieved. The accuracy of the proposed design method is validated through examples. The results demonstrate that the trained deep learning neural network could effectively replace the complex physical mechanisms between structural parameters and sound absorption coefficient curves. This deep learning design method could also be extended to other types of metamaterial reverse designs, significantly enhancing the efficiency of complex metamaterial designs. Lightweight design is crucial for energy saving and emission reduction. With the total mass and average sound absorption coefficient of sound-absorbing materials as targets, the NSGA-II algorithm has been used for multi-objective optimization design. The optimized average sound absorption coefficient increased by 4.84%, and the total material mass was reduced by 18.98%.

A design method to optimize GaN-based class E resonant inductive Wireless Power Transfer systems – application to non-mating connectors

A design method to optimize GaN-based class E resonant inductive Wireless Power Transfer systems – application to non-mating connectors