Advanced high-strength steels (AHSSs) are prone to process defects such as fracture and springback during forming operations. Local warm forming technology represents an innovative forming process that applies targete...
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Advanced high-strength steels (AHSSs) are prone to process defects such as fracture and springback during forming operations. Local warm forming technology represents an innovative forming process that applies targeted heating to specific stamping features of high-strength steel blanks. This study focuses on dual-phase steel DP780 as the research material, obtaining mechanical property parameters at various temperatures through uniaxial tensile tests. Based on investigations into temperature-dependent constitutive models and heat-transfer analysis methods, Abaqus VUMAT and UMAT subroutines were developed using Fortran language to establish a local warm forming simulation algorithm that incorporates predictions of fracture failure and springback. A U-shaped component was designed for local warm forming bend-stretch tests, with experimental data compared against results from the developed algorithm. This validation confirmed the algorithm's capability to accurately predict local warm forming behaviors of U-shaped components. Leveraging the validated algorithm, sensitivity analyses were conducted to examine the influence of local warm forming process parameters on springback, with the response surface methodology employed to quantitatively assess the effects of heating temperature and localized heating zones on springback characteristics.
作者：
Zhao, KaihongTaizhou Univ
Sch Elect & Informat Engn Dept Math Taizhou 318000 Zhejiang Peoples R China
In this paper, we study the solvability and generalized Ulam-Hyers (UH) stability of a nonlinear Atangana-Baleanu-Caputo (ABC) fractional coupled system with a Laplacian operator and impulses. First, this system becom...
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In this paper, we study the solvability and generalized Ulam-Hyers (UH) stability of a nonlinear Atangana-Baleanu-Caputo (ABC) fractional coupled system with a Laplacian operator and impulses. First, this system becomes a nonimpulsive system by applying an appropriate transformation. Secondly, the existence and uniqueness of the solution are obtained by an F-contractive operator and a fixed-point theorem on metric space. Simultaneously, the generalized UH-stability is established based on nonlinear analysis methods. Thirdly, a novel numerical simulation algorithm is provided. Finally, an example is used to illustrate the correctness and availability of the main results. Our study is a beneficial exploration of the dynamic properties of viscoelastic turbulence problems.
Crankshaft is a core part of automobile engine to bear impact load and transmit power. Precision grinding is the most important machining method to achieve high precision of crankshaft main journal. Although many scho...
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Crankshaft is a core part of automobile engine to bear impact load and transmit power. Precision grinding is the most important machining method to achieve high precision of crankshaft main journal. Although many scholars have established various simulation models in the field of cylindrical grinding, it is difficult to carry out effective quantitative simulation for a given crankshaft main journal grinding system. Aiming at the shortcomings of the existing models, a double-rotor dynamic model is proposed, which considers the interaction between the grinding wheel and the main journal, and iterative algorithm is adopted to simulate material removal and roundness change in the grinding process of the main journal. The normal force between grinding wheel and the main journal is defined in detail in the algorithm, which is closer to the actual grinding process. For a given crankshaft grinding system, different grinding strategies of the main journal are quantitatively simulated by using the model. The proposed model and algorithm are validated by experiments, which can provide a basic model for the further study of the crankshaft cylindrical grinding system.
With the development of 3D technology, the construction of 3D motion model has become an important research issue in many fields, such as virtual reality, animation and robot vision. In this paper, a 3D motion model c...
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With the development of 3D technology, the construction of 3D motion model has become an important research issue in many fields, such as virtual reality, animation and robot vision. In this paper, a 3D motion model construction method based on simulation algorithm is proposed. Firstly, the gravity simulation algorithm is used to simulate the trajectory of the object, and the position data of multiple moments with numerical accuracy of 10cm are obtained. Then, the interpolation algorithm is used to interpolate these position data into continuous curves, and the object trajectory with 1cm accuracy is obtained. Finally, we integrate the obtained trajectory data with 3D modeling software to generate a 3D motion model with real motion effect. The experimental results show that this method has high accuracy and reliability in constructing 3D motion model, and is suitable for many fields.
As a new logistics technology, self-driving electric vehicles not only improve freight efficiency but also promote energy saving and emissions reductions. Aiming at logistics technologies based on self-driving electri...
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As a new logistics technology, self-driving electric vehicles not only improve freight efficiency but also promote energy saving and emissions reductions. Aiming at logistics technologies based on self-driving electric vehicles, planning the vehicle scheduling scheme as a whole reduces energy consumption and improves economic and environmental benefits. Targeting an actual freight problem based on a two-way single-lane road connecting the pickup and delivery points and including electric charging stations, this paper proposes a method for optimizing the scheduling scenario and parameters of self-driving vehicles through computer simulations. An optimization model based on dynamic programming is established, and an optimization simulation algorithm is designed to solve the model, effectively solving the overall planning problem of vehicle scheduling. The experimental results show that the model and algorithm have good universality. After specifying an appropriate road length, total number of vehicles, number of spare vehicle batteries, duration of freight transportation, and other necessary information, the simulation algorithm is executed and the optimal scheduling scheme and the total amount of freight transported are output. The efficiency of the algorithm is extremely high, requiring only 1.5 s to complete the whole simulation process of scheduling 150 vehicles for 1000 h over a road with a length of 10 km.
Multitasking has become surprisingly present in our life. This is mostly due to the fact that nowadays most of our activities involve the interaction with one or more devices. In such a context the brain mechanism of ...
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ISBN:
(纸本)9783030549930;9783030549947
Multitasking has become surprisingly present in our life. This is mostly due to the fact that nowadays most of our activities involve the interaction with one or more devices. In such a context the brain mechanism of selective attention plays a key role in determining the success of a human's interaction with a device. Indeed, it is a resource to be shared among the concurrent tasks to be performed, and the sharing of attention turns out to be a process similar to process scheduling in operating systems. In order to study human multitasking situations in which a user interacts with more than one device at the same time, we proposed in a previous work an algorithm for simulating human selective attention. Our algorithm focuses, in particular, on safety-critical human multitasking, namely situations in which some of the tasks the user is involved in may lead to dangerous consequences if not executed properly. In this paper, we present the validation of such an algorithm against data gathered from an experimental study performed with real users involved concurrently in a "main" task perceived as safety-critical and in a series of "distractor" tasks having different levels of cognitive load.
The focus variation microscopy is widely used and researched in both industrial and academic field. But the 3D construction quality of surface topography is affected by the noise, the double peak value, and the discon...
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ISBN:
(纸本)9781510622579
The focus variation microscopy is widely used and researched in both industrial and academic field. But the 3D construction quality of surface topography is affected by the noise, the double peak value, and the discontinuous surface, and so on. A simulation method for focus variation is proposed based on the physical model of optical imaging and the Point Spread Model(PSF). At first, the linear relationship between the blur factor sigma of Gaussian function and the defocus distance delta is deduced which is called point spread parameter lambda, then, considering the positive correlation between blur factor sigma and blur degree, the difference between the real defocused image and the calculated image by Gaussian convolution operation to real captured focused image is shown. It is used to the objective to computed the accurate value sigma and the spread parameter lambda. At last, the difference between focus measure valued of real image sequence and simulation image sequence is used to verify the method. The simulation method is a judgement basis for focus measurement, the single peak of focus curve, and the identification of high-frequency noise.
With the significant rise in demand for same-day instant deliveries, several courier services are exploring alternatives to transport packages in a cost- and time-effective, as well as, sustainable manner. Motivated b...
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With the significant rise in demand for same-day instant deliveries, several courier services are exploring alternatives to transport packages in a cost- and time-effective, as well as, sustainable manner. Motivated by a reallife case study, this paper focuses on developing a simulation algorithm that assists same-day package delivery companies to serve customers instantly. The proposed recommender system provides the best solution with respect to three criteria: cost, time, and sustainability, considering the variation in travel time and cost parameters. The decision support tool provides recommendations on the best alternative for transporting products based on factors, such as source and destination locations, time of the day, package weight, and volume. Besides considering existing new technologies like electric-assisted cargo bikes, we also analyze the impact of emerging methods of deliveries, such as robots and air taxis. Finally, this paper also considers the best delivery alternative during the presence of a pandemic, such as COVID-19. For the purpose of illustrating our approach, we consider the delivery options in New York City. We believe that the proposed tool is the first to provide solutions to courier companies considering evolving modes of transportation and under logistics disruptions due to pandemic.
This paper introduces the concept of simulation algorithm and its application, analyzes the importance of current financial analysis, and establishes the relevant model to analyze and apply the current financial produ...
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This paper introduces the concept of simulation algorithm and its application, analyzes the importance of current financial analysis, and establishes the relevant model to analyze and apply the current financial products. Since the traditional simulation algorithm is not targeted, the simulation algorithm in this paper is effective to change, and then in line with today's financial products. This article is mainly an effective analysis of the value of the stock in the financial product and the value of the securities, so that the portfolio of investment groups that can assist in the investment can be selected.
The continuous wave (CW) illuminator is aimed to simulate high-altitude nuclear electromagnetic pulse. In this article, a simulation algorithm is proposed covering the method of moments and finite difference method (F...
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The continuous wave (CW) illuminator is aimed to simulate high-altitude nuclear electromagnetic pulse. In this article, a simulation algorithm is proposed covering the method of moments and finite difference method (FDM), with the high-speed simulation of the CW illuminator with arbitrary ellipse size, arbitrary loading, and arbitrary polarization direction. Based on the surface electric field equation of the CW illuminator, the mathematical model is established with the vector potential equation and the boundary conditions. In this model, the pulse function and delta function are set as the basis function and the weight function, respectively, for the establishment of the current equation, with the current distribution determined by the simplification equation with image theory and nonuniform FDM. Finally, as the field distribution is determined by the superposition theorem. The simulation algorithm is verified by the self-built CW illuminator.
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