Slice Method Research Articles

A novel Bayesian updating finite element model using enhanced unscented Kalman filter for time-dependent estimation of rockfill dam structure deformation

Due to the time-dependent effect of rockfill dams, the conventional time-invariant finite element method (FEM) can hardly meet practical engineering requirements. This paper proposes an updating Bayesian FEM method for accurate long-term deformation analysis. A combined FEM model is introduced accounting for both instantaneous and creep behaviors. The FEM model is then updated using a Bayesian algorithm, unscented Kalman filter (UKF). The UKF calibrates the prior FEM predictions by incorporating real-time measurement data, thus iteratively reducing discrepancies between model predictions and actual observations. To further enhance the algorithm accuracy, a power-law-based fading memory factor is proposed to mitigate measurement noise in standard UKF. For parameter identification, a slice approach of the high-dimensional covariance confidence ellipsoid is developed. The methodology is validated in Qingyuan rockfill dam, in Guangdong province, China. Results show that the updated FEM is more consistent with the actual monitoring data. The fading memory improves standard UKF performance with a lower relative root-mean-square error (RRMSE). Additionally, the slice method reveals that a specific three-parameter configuration behaves better than the others. The proposed approach can also be extended to other fields including slope and tunneling.

A multi‐layer approach for additive manufacturing of continuous fiber composites

AbstractAdditive manufacturing (AM) of continuous fiber reinforced polymer composites (cFRPCs) requires innovative tool‐pathing strategies that account for the anisotropic properties of the continuous fibers and ensure their continuous deposition as reinforcement along the designed structure, reducing fibers bending and cutting. Existing 3D printing slicing software, designed for isotropic materials like neat polymers, has been adapted for 3D printing of continuous fiber composites, resulting in a layer‐by‐layer approach that necessitates filament cutting after each layer deposition. This method introduces discontinuities, weakening the material and underutilizing continuous fibers strength. In this research, we propose a novel tool‐pathing strategy designed to address these challenges through (1) Ensuring fiber continuity across layers by allowing overlapping filaments and (2) Strategically positioning fiber cut points based on stress distribution, modeled using finite element analysis. A Multi‐Layer Continuous Fiber Path (ML‐CFP) approach was introduced and validated on a simple bracket structure featuring two load‐application inserts. 3D printed brackets using different tool paths were tested to failure under tension and compression after compression molding to improve interlayer adhesion. Mechanical investigations confirmed that the ML‐CFP approach enhances fiber utilization, improving tensile strength and work to fracture by up to 46% and 100% through promoting failure in fibers rather than at cut points.Highlights Introduced the multi‐layer continuous fiber path method (ML‐CFP) in AM of cFRPCs. Introduced the strategic cut point placement (SCPP) based on stress distribution. Maintaining fiber continuity and reduce fiber bending by allowing filament overlap. Mechanical testing to compare the ML‐CFP with conventional slicing methods. Enhanced tensile strength by up to 46% and work to fracture by 100%.

Slope Stability Analysis and Sliding Surface Search Model Based on Swedish Slice Method

Slope Stability Analysis and Sliding Surface Search Model Based on Swedish Slice Method

A comprehensive support-free slicing method library for variable posture additive manufacturing

Support-free slicing technology plays a critical role in additive manufacturing by reducing costs and simplifying post-processing. However, due to the complexity of geometric features, existing support-free slicing strategies often lack the necessary universality in industry. This paper proposes a method library comprising six basic support-free slicing methods to enhance the applicability and computational efficiency. The general methods in the library include facet-based methods and voxel-based methods, the former facilitates rapid slicing, while the latter enables the re-decomposition of complex structural parts. For parts that cannot be covered by general methods, customized methods are developed. These include constructing a support bridge for multi-direction slicing of overhanging regions in an arch model and extracting the optimal central axis for internal channels to achieve precise channel decomposition. Additionally, the methods in the library can be flexibly combined. By recognizing surface features and incorporating manual intervention, models can be decomposed into multiple sub-models, with the most computationally efficient method is matched to each sub-model. The layers and tool-paths of each sub-model are generated by the optimal method. Four typical models are deposited without any support in a five-axis printer to verify the feasibility of the proposed methods.

Numerical analysis and experimental research on the vibration performance of concrete vibration table in PC components

Abstract Vibration table is the key equipment to realize high efficiency and high quality forming and compacting of concrete in prefabricated component (PC) production line, and its performance directly affects the shape quality and compressive strength of PC components. However, the operating parameters of the vibration table are difficult to match the rheology of the concrete during the construction process, which directly leads to a low molding efficiency or unqualified shape quality in the case of slab-type components. Therefore, it is crucial to accurately describe the concrete flow behavior during vibration to improve the construction performance and compaction effect. In this work, the coupled theory of computational fluid dynamics and discrete element is used to study the concrete vibration and compacting characteristics, and the influence of process parameters on vibration performance is analyzed in order to realize the adjustment and optimization of key parameters. First, the concrete solid-liquid two-phase model parameters are calibrated by V-shaped funnel experiments and slump experiments. Then, based on the simulation results, the homogeneity and compactness of concrete are discussed using the segmented sieving method and the slicing method, and the indexes for evaluating the working performance of the vibration table are proposed. Finally, the relationship between vibration frequency (20–30 Hz), vibration amplitude (3–4 mm), and vibration time (15–35 s) and concrete vibration compaction characteristics is investigated to provide a theoretical basis for improving the molding efficiency and mold quality of PC components.

Dynamic modeling and failure mechanism study of herringbone gear planetary transmission system for wind turbine under gear cracks

The herringbone gear planetary transmission system (HGPTS) is a common component in the gearbox of wind turbines. Studying the dynamic performance of gear systems is the key to improving their stability. To reveal the influence of cracks on the dynamic characteristics of the HGPTS, using slicing method, we explore the influence of different crack factors on the time-varying meshing stiffness (TVMS) of the system. A 55-degrees of freedom bending torsion axis pendulum dynamic model was constructed using the centralized mass parameter method; in the model, factors such as TVMS of cracks as well as receding groove and errors are considered. The Runge–Kutta method was used to solve the dynamics, and the evolution diagram of the vibration and load distribution characteristics of the system under crack changes was obtained. Vibration tests were conducted on the system studied in this work. The results show that under the influence of cracks, the TVMS of the external and internal meshing pairs of the system will decrease, and as the cracks intensify, the fluctuation of the TVMS will decrease. Cracks can lead to regular impact behavior in the system. A modulation sideband centered on the meshing frequency appears in the vibration response, and the vibration trajectory of the gears will also become disordered, at the same time, under the influence of cracks, there are significant excitation factors in the load-sharing characteristics of the system. As the cracks continue to intensify, the vibration of the system becomes increasingly evident, and the load-sharing characteristics show a trend of first decreasing and then increasing. The vibration test results are in good agreement with the theoretical predictions. The correctness of the established model is verified. The research results can provide reference for the reliability research of wind turbine HGPTS.

Adaptive remanufacturing for freeform surface parts based on linear laser scanner and robotic laser cladding

Freeform surface parts play a significant role in the aerospace industry, the mold- manufacturing industry and the automobile industry, and it is energy-saving, material-saving, time-saving and environmentally beneficial to remanufacture the damaged components to restore their functionality and performance. Due to the complex geometry of the freeform surface wear, the adaptive remanufacturing of freeform surface parts is confronted with challenges. In this paper, an adaptive remanufacturing method for freeform surface parts based on linear laser scanner and robotic laser cladding is proposed to realize the precise freeform surface measurement and optimized remanufacturing path generation. On the one hand, a systematic wear measurement and assessment method is proposed to precisely locate and quantify the wear. With the noncontact calibration of the laser scanner and industrial robot, the contour of the target surface is real-timely measured and the reverse model is efficiently constructed, which provides detailed 3D morphological information of the worn freeform surface for the latter wear analysis. Next, considering the considerable difference between the reverse model and the nominal model, a refined model aligning method weighted by surface wear segmentation is proposed to minimize the alignment error and, further, the difference entity to be additively manufactured is obtained by discrete model comparison. On the other hand, to cope with the unsatisfactory binding strength over the freeform surface basis and small fragments of the working path for the traditional plane or cylinder slicing method, a novel remanufacturing path generation method is proposed. Considering the curvature distribution of the freeform surface, an optimized equidistant freeform surface slicing method is especially proposed for the difference entity to realize the adaptive fitting to the freeform basin. Furthermore, based on the equivalent volume overlapping model of laser cladding, the cladding track filling method for the freeform surface slicing is designed with the optimized track-to-track distance, which can reduce surface waviness and improve remanufacturing efficiency. Finally, simulations and experiments for the remanufacturing scenario of the steam turbine blade are conducted to verify the validity and feasibility of the proposed adaptive remanufacturing method for freeform surface parts based on linear laser scanner and robotic laser cladding.

Calculation method for static and seismic active earth pressure on counterweight retaining walls under translation based on two critical slip surfaces

The counterweight retaining wall with polyline wall back is a kind of gravity walls, which can be alternatively used in high embankments. To completely analyze active earth pressure on the polyline back under the wall translation mode, a comprehensive method is proposed based on two planar slip surfaces in the retained soil, an inclined slice method within the frame of limit equilibrium, and the pseudo-static approach. Meanwhile, the two critical slip surfaces include the global and local ones in the soils behind the whole wall and only the upper wall, respectively; and mobilized shear strength coefficients on interslice surfaces are introduced to fully consider the interslice shear forces. Some examples show that the proposed resultant forces on the whole wall are close to the experimental and numerical results generally within 10% error. The dip angle of backfill surface has a significant effect on the two slip surfaces, and the inclination of the lower back mostly influences the global slip surface. The unloading effect of the platform on the lower earth pressure becomes obvious as the upper wall lengthens under a constant height of the whole wall. The magnitude and profile of the seismic earth pressure on the polyline back are greatly influenced by the seismic coefficients.

Designing 3D-printed concrete structures with scaled fabrication models

This article proposes using scaled fabrication models to assist the design research of 3D-printed discrete concrete structures where full-scale fabrication tests are costly and time-consuming. A scaled fabrication model (SFM) is a scaled model 3D-printed the same way as in actual construction to reflect its fabrication details and acquire alike layer line textures. The components of a 1:10 SFM can be easily produced by consumer-level desktop 3D printers with minimal modification. SFMs assist the design communication and make possible quick tests of distinct fabrication designs that are hard to assess in digital modeling during the conceptual design phase. A case study of a discrete compression-dominant funicular floor derived from graphic statics is presented to illustrate the contribution of SFM to the design research of force-informed toolpathing where the printing direction of a component is aligned to the principal stress line. The design iterations encompass a sequence of component, partial, and full model SFM printing tests to explore and optimize the fabrication schemes where parallel, non-parallel, and creased slicing methods to create toolpaths are compared and chosen to adapt different discrete components.

A New Hybrid Classification Framework in Childhoods Allergies with Dataset Slicing Method

Childhood allergies, particularly food allergies, are growing more frequent. Their major influence on children's health and well-being has piqued the interest of worldwide public health officials. The increased prevalence of childhood allergies in Turkey, where these patterns are also relevant, adds urgency to the need for effective classification and management options. This study addresses the shortcomings of simple classification algorithms in obtaining high accuracy by presenting a novel hybrid classification methodology. The research creates a novel method where three different prediction models are built by combining Support Vector Machine and Decision Tree classifiers. This method improves the classification process by taking into account instances that have been incorrectly classified as possible sources of useful information instead of just being noise. This instance filtering-based hybrid classification algorithm that is used in this study maintains the simplicity of interpreting learning outcomes while achieving comparatively high accuracy. Extensive experiments on the allergy dataset show the effectiveness of this hybrid approach, with an impressive accuracy of 0.906. This greatly outperforms the fundamental classification algorithms. The experimental outputs have important implications for medical professionals. This study might add a valuable contribution to the literature by giving a fresh solution to childhood allergy classification.

Response of hypoxia to future climate change is sensitive to methodological assumptions

Climate-induced changes in hypoxia are among the most serious threats facing estuaries, which are among the most productive ecosystems on Earth. Future projections of estuarine hypoxia typically involve long-term multi-decadal continuous simulations or more computationally efficient time slice and delta methods that are restricted to short historical and future periods. We make a first comparison of these three methods by applying a linked terrestrial–estuarine model to the Chesapeake Bay, a large coastal-plain estuary in the eastern United States. Results show that the time slice approach accurately captures the behavior of the continuous approach, indicating a minimal impact of model memory. However, increases in mean annual hypoxic volume by the mid-twenty-first century simulated by the delta approach (+ 19%) are approximately twice as large as the time slice and continuous experiments (+ 9% and + 11%, respectively), indicating an important impact of changes in climate variability. Our findings suggest that system memory and projected changes in climate variability, as well as simulation length and natural variability of system hypoxia, should be considered when deciding to apply the more computationally efficient delta and time slice methods.

Analysis of the dynamic contact behaviour of high-speed train transmission gear excited by wheel defects

Studies on wheel flatness and polygonal wear have demonstrated that wheel defects cause severe impact forces at the wheel–rail interfaces. This study investigated the dynamic contact mechanical behaviour of high–speed train transmission gears when subjected to wheel defects. First, a train-track coupling dynamics model was established, considering the localized contact characteristics of transmission gears. This model was developed using the slice method and the Hertz contact model, exploring the spatial coupling effects between the gear contact interface and the train–track interface. Subsequently, the dynamic model was employed to extract essential contact mechanical parameters of the transmission gear under the influence of wheel defects, including gear meshing load, gear contact stress, and sliding velocity. Furthermore, an analysis was conducted to uncover and elucidate the mechanism by which wheel flatness and polygonal wear impact the dynamic contact behaviour of the transmission gear. This study underscores the importance of considering wheel defects when assessing the contact fatigue and wear performance of high-speed train transmission gears.

An accurate slicing method for dynamic time warping algorithm and the segment-level early abandoning optimization

Time series data analysis algorithms have been gaining significant importance in the research community. Extensive studies have confirmed that Dynamic Time Warping (DTW) is the best distance measure in time series analysis across multiple domains. However, DTW is a time-consuming algorithm with quadratic time complexity, which limits its widespread adoption. In this paper, we proposed a novel slicing mechanism for DTW, called Partial Dynamic Time Warping (PDTW). PDTW is capable of dividing a complete DTW calculation into multiple independent partial calculations. The proposed PDTW ensures very consistent alignments with the original Constrained DTW (CDTW) by incorporating additional data windows for each pairwise time series. On the basis of PDTW, we also present Early Abandoning Dynamic Time Warping (EADTW) technique, which saves a substantial amount of computing time by abandoning superfluous calculations of unnecessary segments in the time series classification task. Large-scale experimental results on 96 datasets from the UCR archive show the effectiveness of PDTW and EADTW. The cumulative sum of PDTW distances for segments is nearly identical to the CDTW distance, and in many cases, it is exactly equal. This remarkable characteristic of PDTW indicates its immense potential for further development and optimization of DTW, such as parallelization. In classification tasks, EADTW is 1.99 times faster than CDTW on average, with a maximum speedup of 2.89 times, while maintaining accuracy. Additionally, it enhances accuracy by 0.93% and improves speed by 2.34 times under the accuracy priority parameter.

Model and new imbalance thrust force method mechanical model for thrust-type soil landslides

The slice method used in traditional slope stability analysis has been improved, but the development of monitoring technology means that its assumption of the rigid contact condition has become inapplicable. This study considered the case of the Ya'an Baoxing landslide, which is a thrust-type soil landslide in Sichuan Province (China). First, on the basis of the Imbalanced Thrust Force Method, a mechanical model with a Kelvin body added between the slice blocks was established, and the slice block velocity formula was derived using the dynamic differential equation. Notably, this model is currently at the stage of qualitative research and more effective simplification methods are required; however, this study does promote both a new concept for the slope stability method and a new approach to landslide mechanism analysis. Comparison of model test monitoring data and the analytical results revealed that the mechanical model could effectively reflect the internal mechanical transmission law of the thrust-type soil landslide. It verified that the landslide evolution process conformed to the Saito model, and revealed that the unbalanced force of the non-disintegrated landslide, which followed the law of internal force transmission from the top to the foot of the slope, initially rose and then fell rapidly. Finally, the interaction mechanism between the ideal elastoplastic anchor cable and the slope was examined based on engineering experience. This study innovatively reinterpreted the traditional slice methods, explored and proved to a certain extent the transmission mode of internal stress in a thrust-type soil landslide, and verified the possibility of achieving high-precision monitoring and early warning of slope instability using a mechanical monitoring method.

Features of determining the location of the reference image on the current half-tone using the method of binary slices

Features of determining the location of the reference image on the current half-tone using the method of binary slices

An evaluation of a novel method for the MRI-based assessment of Caton-Deschamps index in the Knee

IntroductionThe radiographical assessment of patella height has historically been performed using X-Ray. The aim of this study was to evaluate a new method for the assessment of patella height using MRI and to assess the correlation with the X-Ray based assessment.Materials and methods159 patients who had both lateral radiographs and MRI images were included. Parameters measured included traditional radiographical CDI, MRI-based CDI, and TT-TG distance. On the basis of the TT-TG, the patients were divided into 2 groups. Two different methods were used to assess CDI using MRI: using a single slice image, and an alternative technique using two different cross-sectional images. The correlation of the two measurement methods was assessed using Pearson’s correlation coefficient. The intraclass correlation coefficient (ICC) was determined from the measurements of the two investigators.ResultsThe average TT-TG distance was 11.6 mm (± 4.6). In patients with a TT-TG < 15 mm, both measurement methods showed comparable correlation with measurements on X-Ray. In patients with a TT-TG of > 15 the the new cross-sectional imaging method showed higher correlation with traditional X-Ray assessment compared to CDI assessment using the traditional single slice method (r = 0.594, p < 0.001 vs. r = 0.302, p = 0.055).ConclusionsThe assessment of CDI on MRI using a cross-sectional imaging method has a better correlation with traditional X-Ray assessment of CDI than single-slice assessment. This is particularly true in patients with elevated TT-TG and as such should be preferentially used in the assessment of Patellar height in this cohort.

Adaptive Slicing Method for Hermite Non-Planar Tessellated Surfaces Models

This paper presents an adaptive slicing method for Hermite non-planar tessellated surfaces models to improve the geometric accuracy of Rapid Prototyping (RP). Based on the bending characteristics of Hermite curved triangles, a slicing method for a complete Hermite surface model, including the grouping, the construction of the topological relationships, and the calculation of the intersection contours, was employed. The adaptive layering method considering the normal vector at the vertexes of the Hermite curved triangles was employed to grain the variable thickness of all layers of the Hermite surface model. The classical Stanford bunny model illustrates the significant improvement in the accuracy of the proposed method compared to the traditional method.

Upper-Bound Limit Analysis of the Multi-Layer Slope Stability and Failure Mode Based on Generalized Horizontal Slice Method

Upper-Bound Limit Analysis of the Multi-Layer Slope Stability and Failure Mode Based on Generalized Horizontal Slice Method

Analisis Perbandingan Arus Jenuh Pada Pendekat Terlindung Simpang Diponegoro-Pilau-Nenas Dengan Metode MKJI Dan Time Slice

Over time the number of vehicles has increased due to improved urban conditions. This affects the emergence of problems in the Palangka Raya urban transportation system, which has an impact on the performance of the road network, especially the performance of signalized intersections. The purpose of this research is to calculate the value of saturation current (S) using the IHCM 1997. In order to analyze the saturation flow and road performance on the Diponegoro - Pilau - Nenas approach, Primary data and Secondary data are required, Primary data includes intersection geometric data and traffic volume in green hours. While secondary data includes location maps and population. In analyzing the comparison of saturated flow refers to the IHCM 1997 and the Time Slice method. The results of the comparison analysis of saturated flow with IHCM 1997 and Time Slice method on each approach A, B, C, and D respectively are 12.64%, 27.52%, 14.94%, and 36.94%. Also obtained the highest DS value using the saturated flow value of IHCM 1997 and Time Slice method is on St. Pilau which is respectively 1.09 included in the level of service F, and 0.93 included in the level of service E, then from the results of this analysis can be known by using the results of the calculation of saturated flow of Time Slice method there is an increase in the value of Level of Service (LOS).

A vibration model of a flexible multiple shaft gear system with the tip relief modification

The fixed-shaft gear system (FSGS) is one critical part in gear transmission systems (GTSs), whose vibrations can significantly influence performances of GTSs. To reduce the vibrations of rigid FSGS caused by installation and manufacture errors, the tooth profile modifications without the shaft deformation were widely introduced. This paper establishes a flexible multiple shaft gear system (FMSGS) model of an unmanned underwater vehicle, which can obtain vibrations of rotor at different axial positions. However, the previous rigid FSGS model cannot obtain those vibrations. In the FMSGS model, the Timoshenko beam elements are applied to the establishment of shaft segments considering flexibility. The meshing stiffness for helical gears with different ranges of tooth profile modification are quantitatively expressed by a gear slicing method. Based on the kinetic relationship between the gear pairs, shaft segment, and bearings, the dynamic equations of FMSGS are derived. By comparing the time-domain waveforms and spectra of FMSGS, the effects of the tooth profile modification amounts and lengths on the vibrations of FMSGS are revealed. The proposed FMSGS model is validated by an experiment. This study extends the dynamic methods of FSGSs, and some suggestions on the vibration control of FSGSs are given.