Layout Angle Research Articles

Shear behavior of pre-damaged RC beams strengthened with UHPFRC-CFRP grid layer

Ultra-high performance fiber reinforced concrete (UHPFRC), incorporating recycled tyre fibers, and carbon fiber-reinforced polymer (CFRP) grid were utilized to strengthen the pre-damaged reinforced concrete beams caused by coupling action of sustained loads and marine environment. The failure modes, characteristic loads, deflection features, and strain behavior of the strengthened beams with various types of UHPFRC, thicknesses of UHPFRC layers, CFRP grid ratios, and CFRP grid layout angles were investigated. The results indicated that they exhibited the typical shear failure, and their characteristic loads increased by 102 %–205 % compared to the undamaged beam. By increasing the thickness of the UHPFRC layer and the CFRP grid ratio, and adopting 45° CFRP layout angle, the cracking stiffness, energy absorption capacity, and shear force sharing ability would be further improved, while adopting the UHPFRC incorporating recycled tyre fibers would decrease the ductility. Moreover, analytical models were developed to calculate the ultimate loads, manifesting reasonable accuracy.

Channel deformation around non-submerged spur dikes with different alignment angles under ice cover

Abstract This study explores how the ice cover on water surfaces affects the deformation of the channel bed around non-submerged spur dikes. Laboratory experiments have been conducted by using two types of model ice cover with different roughness coefficients and three sands with different median grain sizes. The effects of various layout angles of non-submerged spur dikes on the maximum scour depth and scour patterns around spur dikes have been evaluated. Results showed that the dike orientation angle is the critical factor influencing the maximum scour depth. The presence of an ice cover and its roughness coefficient dramatically affect the channel bed deformation around spur dikes. The combined effect of the dike orientation angle, ice cover roughness, and flow Froude number resulted in different scour patterns. For instance, the upstream length of scour holes decreases by approximately 60% when the dike angle changes from 90º to 60º, while an increase in flow rate by about 50% leads to a 20% increase in the downstream length of scour holes. Equations have been derived to determine the maximum scour depth around spur dikes, considering the effects of ice cover, bed material and the dike layout angles.

Surface stress redistribution and thermal performance of tempered vacuum glazing with printing sintering support pillars

The support stress distribution of the printing sintering support pillars (PSSP), which became rounded due to the shrinkage that occurred in sintering formation, was different from that of the conventional cylindrical metal support pillars (CMSP). In this paper, ANSYS software was used to establish the mechanical simulation model of tempered vacuum glazing with PSSP. The influence of PSSP arrangement (spacing D, and three arrangement styles of square, regular triangle, and regular hexagon) on the mechanical properties of tempered vacuum glazing were analyzed, including the maximum stress σ1max on tempered glass (T-glass) surface, the maximum deformation ω1max of T-glass, and the maximum stress σ2max on the PSSP. The simulation results showed that when the PSSP were arranged in a square with D of 50 mm, σ1max, ω1max, and σ2max were 26.39 MPa, 7.82 μm, and 546.72 MPa, respectively, which met the requirements of the evaluation indexes of mechanical properties of tempered vacuum glazing, and had the least number of PSSP. The mechanical properties of tempered vacuum glazing with regular triangle arrangement of PSSP were better than those of square and regular hexagon arrangements, and the σ1max, ω1max and σ2max of which were 16.24 MPa, 7.25 μm and 489.66 MPa respectively, but with a too large number of PSSP. Optimization of the triangle layout angle and side length could reduce PSSP numbers. When the PSSP were arranged in an isosceles triangle with a 65° base angle and 50 mm bottom length, the mechanical properties of tempered vacuum glazing were the best. The triangular arrangement of PSSP had an optimization effect on the surface stress redistribution of tempered vacuum glazing, and the number of stress peaks was twice that of the square arrangement. Meanwhile, tempered vacuum glazing samples were made and the surface stress, thermal conductivity tests were conducted. The results showed that the measured values of peak and valley stress had an error of ±2.8 MPa compared to the simulated values. The simulation results were reliable and the surface stress redistribution of tempered vacuum glazing was present. The measured heat transfer coefficient of tempered vacuum glazing with PSSP was 0.7402 W m−2 K−1, slightly higher than that of tempered vacuum glazing with CMSP. The difference between them was not significant.

Deformation characteristics of a ring-stiffened cylindrical shell induced by shock waves and coalesced bubbles in double-charge underwater explosions

This study investigates the deformation characteristics of a ring-stiffened cylindrical shell induced by shock waves and coalesced bubbles in double-charge underwater explosions. A numerical model for coupling underwater multi-point explosion loads with the cylindrical shell is established by the Arbitrary Lagrange Euler method, and underwater explosion experiments with double charges are also conducted. The numerical model's effectiveness is validated by comparing shock wave superposition characteristics, bubble coalescence processes, and bubble pulsation periods with the experimental results. Based on the numerical model, the influences of detonation intervals and layout angles of charge on shock wave superposition effects, temporal and spatial distribution characteristics of shock waves, and the evolution process of coalesced bubbles in underwater explosions with double charges are explored. Additionally, the deformation characteristics of cylindrical shells induced by shock waves and coalesced bubbles for double charges with different detonation intervals and layout angles of charge are analyzed. The results indicate that double charges can induce more substantial deformation on the cylindrical shell at a specific detonation interval than a single charge with equal total mass. During the shock wave phase, the cylindrical shell's deformation decreases nonlinearly with an increased layout angle. Conversely, during the bubble load phase, the deformation of the cylindrical shell shows an approximately linear decrease with an increase in layout angle. A critical angle exists, below which the impact of double charges on the cylindrical shell is more substantial when detonated with an interval than simultaneous detonation.

Influence of the Advance Jacked Pipe on the Jacking Force of the Subsequent Pipe Based on Pipe–Soil Full Contact Model

Abstract In pipe jacking engineering, accurate prediction of jacking force is the key to pipe jacking design. Based on a project of the Beijing Daxing Airport Line, the influence of the advance jacked pipes on the jacking force of the subsequent pipe is carried out in the present work. First, the verified numerical model of practical engineering was established, and the jacking force and radial stress of different pipes were analyzed. Then, the two pipes were taken as research object, and the parameters of spacing, angle, buried depth, and pipe diameter were investigated, respectively. The results show that in the actual project, the advance jacked pipes have amplification and superposition effects on friction resistance of the subsequent pipe, and the maximum growth rate is 37.2%. The friction resistance of the subsequent pipe presents a trend of first increasing and then decreasing with the change of the layout angle of advance jacked pipe from 0° to 180°. With the increase of buried depth and pipe diameter, the absolute value of incremental friction resistance of the subsequent pipe increases gradually, but the growth rate remains constant. Finally, the empirical formulas for predicting the friction resistance growth rate of subsequent pipes under different angles are proposed. The research results can provide some reference for the design of pipe jacking.

Experimental study of peripheral fuel injection for higher performance in diesel engines

In conventional diesel combustion (CDC), a centrally located multi-hole injector supplies fuel radially outwards. This study introduces and explores the concept of peripheral fuel injection (PeFI) to supply fuel from multiple locations on top of the combustion chamber using several single-hole injectors. The PeFI concept is designed to eliminate flame-wall and jet-wall interactions, and, ideally, to produce independent flames without any interference. PeFI is also intended to increase air entrainment in the near field and thus, reduce equivalence ratio at the lift-off length and subsequent soot formation. PeFI reduces wall heat transfer compared to CDC although this feature is not considered in the present study. The two methods of fuel injection are compared in a non-reacting optical chamber via high-speed imaging of the jets. N-heptane fuel at 1500 bar supply pressures is injected into a test chamber filled with nitrogen at engine relevant ambient densities of 23.0 and 18.5 kg/m3. Four configurations are trialed including a six-hole central injector and six, single-hole PeFI injectors with holes oriented at a layout angle, defined as the angle between the center of the fuel jet and chamber radius, of 0°, 15°, and 30°. Flow visualizations show jet-to-jet interactions at small layout angles for PeFI, but little to no jet-to-jet (or jet-wall) interference as the layout angle increases to 30°. Image analysis reveals that PeFI provides faster rate of injection, longer jet penetration length, greater width near the jet tip, and larger jet volume compared to those for the central injector. Overall, results demonstrate the potential of PeFI to simultaneously improve fuel efficiency and reduce emissions in diesel engines.

ELASTIC AND STRENGTH PARAMETERS DETERMINATION OF POLYMER COMPOSITE MATERIALS AND CYLINDRICAL SHELLS

The article presents a method for layout optimization in polymer composite materials that allows to assess their strength. In order to assess the stress-strain state of each layer, an orthotropic elasticity model is used assuming that the fibers in the material are parallel. The behavior model of polymer composite materials is based on the Hashin criterion, which makes it possible to separate the destruction mechanisms of matrix and fiber. The strength assessment was carried out in accordance with the structural approach involving studying the strength of each layer separately. The parameters of the deformation model and the Hashin strength criterion were determined based on the results of testing. Tests were carried out on unidirectional polymer composite materials samples cut at angles of 0, 90 and 45° to the direction of reinforcement. The verification was based on the results of bending tests of polymer composite materials samples. Verification showed high proximity between the calculation results and the experimental data. A method for selecting the layout angles of each layer of polymer composite materials has been developed making it possible to calculate the greatest strength of the cylindrical shell under various external loads. The method involves determining the stresses in each of the polymer composite materials layers, as well as Hashin indicators corresponding to the destruction of the fiber or matrix under tension or compression. Based on the indicator values, the optimal angle and layout pattern can be selected, providing the greatest margin of safety for the shell. This method allows for a preliminary assessment of the safety factor of cylindrical shells made of polymer composite materials based on the experimentally determined elastic parameters of the material and the parameters of the Hashin strength criterion. The method takes into account the angle and layout of the prepreg under the influence of internal pressure, axial compressive force and torque.

Comparative techno-economic assessment and minimization of the levelized cost of electricity for increasing capacity wind power plants by row and angle layout optimization

This work presents techno-economic assessment and optimization results for wind power implementation. The results constitute an attempt to provide recommendations on optimal design configurations and operating conditions for future possibilities of installations in Kuwait, where the wind speed is at maximum levels at high altitudes during the early daytime and late nighttime, whereas in the afternoon, the wind speed reaches its maximum at low altitudes. This cyclic behavior indicates that the wind speed and direction change in a predictable pattern, benefiting wind power generation. The techno-economic assessment and optimization are performed for multi-row design configurations of power plants. The selection using an optimal method comes through evaluating 2220 configurations, from which 60 optimal configurations are determined for different variations of the number of rows in the wind power plant (Nr) based on the minimization criterion of the Levelized Cost of Electricity (LCOE). The optimal configurations have optimal wind power plant layout angle (θplant). Some of the main findings are as follows:(i) the Nr and θplant values impact the LCOE, wake losses, performance ratio, capacity factor, and annual gross energy. (ii) The wind power density is calculated to be 289 W/m2, (iii) June and July have high levels of generation, wind speed, temperature, and humidity, (iv) there exists an exponential relation between the installed cost per watt and Nr. (v) The present value of annual energy, net present value (annual costs), annual energy, and annual gross energy have increasing linear trends as Nr increases, and (vi) the optimal configurations require a power purchase agreement price of at least 7.03 cent/kWh to make a positive return on investment.

Study on the influence of layout angle on static stiffness and longitudinal grip of tread blocks

The static stiffness and longitudinal grip of the tread block are important parameters of the tire, affecting the performance of the tire, such as braking, steering, noise, and side slip properties. In order to study the influence of the layout angle of the tread block on the static stiffness and longitudinal grip of the tread block, a theoretical model of the change of the static stiffness of the tread block with the layout angle is introduced, which is considered the effect of the compression on the deformation under sliding conditions. A finite element model of the static stiffness of the tread block changing with the layout angle is established in ABAQUS, and the conclusions obtained are in good agreement with the theoretical model. On this basis, the changes in the longitudinal grip of the tread block under different layout angles are explored, and the longitudinal grip of the tread block is increased and then decreased with the increase of the layout angle, and the increase rate before reaching the peak is less than the decrease rate after reaching the peak. Comparing and analyzing the shear stress nephogram of the load-bearing slip tread block under different layout angles, it is found that when the layout angle changes, the shear stress of the tread block will be redistributed according to certain characteristics, thus affecting the longitudinal grip of the tread block.

Influence of layout angles on river flow and local scour in grouped spur dikes field

The flow properties, sediment moving and geomorphology in the grouped spur dikes field have always been of interest in river engineering. In this paper, a 3D numerical model is employed to investigate the flow motion and riverbed scouring around grouped spur dikes with different layout angle styles. Series of flume experiments are introduced to verify this model’s reliability before its application on the simulation of the downward-angled spur dikes case and normal-angled spur dikes case respectively, and detailed comparative analyses on the flow intensity, vortex patterns and local scour are made for these two layout angle styles respectively, in which the similarities and differences could both be found. Then the influence of flow conditions, sediment parameters and spur dike layout angles on the maximum scour depth and their coordinates are discussed through additional simulations, while the different correlations show between the maximum scour depths with these three factors. Then the simulation of flood passage through the spur dike fields is conducted, which could not only provide river hydrological information but also offer guidance for the hydraulic structure safety.

Impact mechanism of the chip muffler on the cooling performance of super large-scale natural draft wet cooling tower under crosswind

• 3D numerical simulation on S-NDWCT with chip muffler is carried out. • The chip muffler enhances the cooling efficiency of S-NDWCT under crosswinds. • The positive effect of the chip muffler on the S-NDWCT varies with layout patterns. • The optimal pattern of chip muffler is proposed based on the tower performance. The noise attenuation of cooling towers mainly relies on the chip muffler, of which the layout pattern exerts a non-negligible impact on the cooling effect. This paper analyzes the impact mechanism of the chip muffler’s layout pattern on the cooling performance of a super large-scale natural draft wet cooling tower (S-NDWCT) through a three-dimensional numerical study. The layout patterns of chip muffler include three installation angles ( θ = 0°, 15° and 30°), three distances between the muffler and cooling tower ( L = 0.0 m, 2.5 m and 5.0 m), and two layout angles of the muffler ( α = 180° and 360°). Results manifest that the chip muffler can enhance the cooling performance of S-NDWCT by improving the airflow uniformity in the tower. The optimal layout pattern is L = 0.0 m, θ = 0° and α = 360°, under which the increment of circulating water temperature drop reaches a maximum of 1.04 ℃. The ventilation rate increases with the increase of L and the decrease of θ . The Merkel number increases with the decrease of L and θ . The circulating water temperature drop increases with the decrease of θ and shows little regularity with L . This paper can provide the reference for optimizing layout patterns and engineering applications of the chip muffler.

Geometry and size optimization of stiffener layout for three-dimensional box structures with maximization of natural frequencies

Based on the growth mechanism of natural biological branching systems and inspiration from the morphology of plant root tips, a bionic design method called Improved Adaptive Growth Method (IAGM) has been proposed in the authors’ previous research and successfully applied to the reinforcement optimization of three-dimensional box structures with respect to natural frequencies. However, as a kind of ground structure methods, the final layout patterns of stiffeners obtained by using the IAGM are highly subjected to their ground structures, which restricts the optimization effect and freedom to further improve the dynamic performance of structures. To solve this problem, a novel post-processing geometry and size optimization approach is proposed in this article. This method takes the former layout optimization result as start, and iteratively finds the optimal layout angles, locations, and lengths of stiffeners with a few design variables by optimizing the positions of some specific node lines called active node lines. At the same time, thicknesses of stiffeners are also optimized to further improve natural frequencies of three-dimensional box structures. Using this method, stiffeners can be successfully separated from their ground structures and further effectively improve natural frequencies of three-dimensional box structures with less material consumption. Typical numerical examples are illustrated to validate the effectiveness and advantages of the suggested method.

Research on the rectangular clinching process for metal and polyoxymethylene sheets

AbstractPolyoxymethylene (POM), as an energy‐saving material, is widely applied in the manufacturing field. Yet, research on the rectangular clinching process between metal and POM sheets is still lacking. In this paper, the rectangular clinching process for POM and Al5052‐H32 plates was investigated. The feasibility of the metal–polymer hybrid component had been analyzed in terms of diverse forming forces and diverse joint layout angles, respectively. The mechanical characteristics were appraised by the lap‐shear test. The failure modes of rectangular clinched joints produced under diverse forming conditions had also been analyzed. The results showed that the optimal forming force of rectangular clinched joints was 14 kN, in which the lap‐shear strength was 1090 N. Furthermore, the rectangular clinched joints produced under the joint layout angle of 90° could withstand the maximum lap‐shear load (1415 N) under the optimal forming force. The failure mode was the separation of two plates and the fracture of the bridge structures.

Buckling Analysis and Optimization of Stiffened Variable Angle Tow Laminates with a Cutout Considering Manufacturing Constraints

Variable angle tow laminates (VAT) and stiffeners are known to redistribute the in-plane load distribution and tailor the buckling mode shapes, respectively, for improving structural performance. To leverage the benefits of using VAT laminates in the practical applications, in the present paper, we discuss buckling load maximization conducted for a stiffened VAT laminated plate with a central cutout considering VAT laminate manufacturing constraints. Three representative boundary conditions as seen in the aerospace structures are considered: in-plane axial displacement, in-plane pure shear, and in-plane pure bending displacements. Two common manufacturing constraints, the one on the automatic fiber placement (AFP) manufacturing head turning radius and the other on the tow gap/overlap, while fabricating VAT laminates are considered in the laminate design. These two manufacturing constraints are modeled by controlling the fiber path radius of curvature and tape parallelism in optimizing the fiber path orientations for the VAT laminates. Stiffener layout and fiber path angle for the VAT laminated plates are both considered in the buckling load maximization study. To avoid using a fine mesh in modeling the stiffened VAT laminates with a cutout when employing the finite element analysis during the optimization, the VAT laminated plate and the stiffeners are modeled independently. The displacement compatibility is enforced at the stiffener–plate interfaces to ensure that the stiffeners move with the plate. Particle swarm optimization is used as the optimization algorithm for the buckling load maximization study. Optimization results show that, without considering AFP manufacturing constraints, the VAT laminates can increase the buckling loads by 21.2% and 12.4%, respectively, comparing to the commonly used quasi-isotropic laminates and traditionally straight fiber path laminates for the structure under the in-plane axial displacement case, 19.7% and 12.5%, respectively, for the in-plane shear displacement case, and 62.1% and 26.6%, respectively, for the in-plane bending displacement case. The AFP manufacturing constraints are found to have different impacts on the buckling responses for the VAT laminates, which cause the maximum buckling load to be 9.3–10.1%, 3.0–3.2%, and 23.2–29.8% less than those obtained without considering AFP manufacturing constraints, respectively, for the present studied model under in-plane axial, shear, and bending displacements.

A Comparative Study between Polyline and Straight Line Arrangements of Antislide Piles Based on Soil Arching Effect

Considering the limitations of terrain and engineering expenses, antislide piles are sometimes arranged in polylines. Studies show that this arrangement adversely affects the mechanical characteristics of antislide piles. However, there is no in‐deep understanding of this issue and the structural design and calculation method of this arrangement have not been discussed in relevant standards. Aiming at resolving this shortcoming, the polylines pile arrangement is studied in this article to provide a scientific basis for designing and calculating antislide piles. To this end, the cantilever pile is taken as the research background, and the soil arching effect between piles is taken as the research object. Then the performances of the single‐row polyline pile layout and straight line pile layout are analyzed in the Dawanjiang landslide and the results are verified from the aspects of the landslide reinforcement and the influence on the antislide pile structure. The obtained results show that the polyline pile layout is disadvantageous to the safety of the antislide pile structure, and the soil arch between piles under the polyline pile layout condition is not uniform. Meanwhile, it is found that as the polyline pile layout angle increases, the stress concentration appears at the “inflection point.” Under this circumstance, the soil arch between piles is not uniform, and the stress concentration intensifies.

An On-Site Harmonic Noise Cancellation Antenna With a Multinode Loop for Magnetic Resonance Sounding Measurement

Magnetic resonance sounding (MRS) is a geophysical method to detect aquifers directly in the earth’s magnetic field, which offers the benefit to evaluate groundwater qualitatively and quantitatively. Due to the influence of powerline harmonic noise, the reliability of obtaining the weak MRS signal (10–9 V) is severely limited with a square antenna or a conventional <xref ref-type="fig" rid="fig8" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">figure-8</xref> antenna. To realize the high signal-to-noise ratio (SNR) measurement of groundwater, we first propose a multinode antenna consisting of four <xref ref-type="fig" rid="fig8" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">figure-8</xref> antennas connected around nodes, which has better geometric symmetry and antiphase magnetic dipoles to cancel the magnetic fluxes caused by noise. The simulation results show that the noise suppression effect of the new antenna is better than that of the square antenna and <xref ref-type="fig" rid="fig8" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">figure-8</xref> antenna and is independent of the layout angle. We successfully applied the multinode antenna to test the noise-canceling ability in the urban environment and the detection of field underground aquifers, which verified the superiority of the new antenna in improving the efficiency and the SNR. To be specific, the adoption of this antenna can increase the detection efficiency by 4–8 times and improve the SNR by 10 dB with the same sensitivity compared with the conventional antennas. The utilization of on-site noise suppression characteristic in multinode antennas provides a novel idea for MRS with high SNR, especially in areas with severe noise interference.

A 6-PTRT Parallel Robot using Parallel Guide Wires

In this paper, a parallel guide 6-PTRT parallel robot with 6 degrees of freedom is designed for drilling and riveting in the narrow space inside the nacelle, and its kinematics analysis is performed, including the solution of inverse kinematics solution, Jacobian matrix, workspace results and the forward kinematics solution. The major structure parameters of the parallel robot are optimized by integrating the global performance index and the size of the workspace, and a set of parallel robot size parameters with good comprehensive performance are obtained. They are layout angles θ 1 = 17.5°, θ 2 = 15°, radius of movable platform r = 130mm, radius of fixed platform R = 220mm, length of branch chain L = 220mm. These parameters meet the given size of the space available for the robot and the mounting dimensions of the drilling tool

Study on the influence of steel layout on steel reinforced concrete pier structure

In order to study the influence of the steel reinforced concrete pier structure by the steel layout, ANSYS software was used to construct a structural model of the steel reinforced concrete pier, by studying the effect of three different layout numbers on the pier crack development, pier stress and section steel stress under two different working conditions, it is concluded that the three-section steel cloth is the optimal layout. Based on this, we continued to study the influence of the layout angle and layout size on the structure of the pier, and finally concluded that the layout was optimal when the layout angle of the three-section steel was 12.5 ° and the layout size was two short and one long. The research results provide theoretical support for the design of steel reinforced concrete pier structures.

Tuning energy harvesting devices with different layout angles to robust the mechanical-to-electrical energy conversion performance

This research presents an engineering approach to fabricate multilayered electrospun nanofiber mats with high conversion performance of mechanical to electrical energy as well as improved physical stability. Electrospun polyvinylidene fluoride nanofiber webs were prepared with predefined nanofiber alignments. Fiber alignments and layer-by-layer deposition angles are considered as a tool to adjust the piezoelectric responses of multi-layered fibrous mats. Samples with optimized drum speed and maximum aligned nanofibers were utilized to fabricate multi-layered mats in different layering angles from the fiber direction of base layer (0°, 30°, 60°, 90°, 120°, 150°, and 180[Formula: see text]). The effect of layering angle of multi-layered nanogenerators on their piezoelectric responses was investigated using an image analysis approach based on the fast Fourier transform. Multivariate analyses (ANOVA) performed to reveal the relationship between increasing drum speed and nanofibers alignment and the degree of crystallization as well as the formation of β-phase in the fiber crystalline structure. Results showed that increase in drum speeds had a relative improvement in the crystal structure and the formation of β-phase in the electrospun polyvinylidene fluoride nanofiber webs. Furthermore, electrical response of samples with well-aligned polyvinylidene fluoride nanofibers collected at 1800 r/min led to 94.49% improvement when they were exposed by a periodic mechanical impact compared to non-aligned polyvinylidene fluoride nanofiber webs. Piezoelectric response of multilayered samples with layering angles of 120[Formula: see text] showed 41% improvement in their electrical output compared to those with 0[Formula: see text]. These results teach us to establish engineering design rules for textile-based energy conversion devices with different piezoelectric coefficients.

A GHz rotary nanoflake driven by diamond needles: A molecular dynamics study

In this study, we build a nanostirrer, in which the circular graphene nanoflake can be driven to rotate on graphite substrate by four wedged diamond needles (DNs). Molecular dynamics simulations reveal that the rotationally distributed DNs provide strong repulsion to the nanoflake via their tip atoms. Once the circumferential component of the repulsive force is non-zero, it actuates the flake to rotate at gigahertz. The stable rotational frequency (SRF) of the flake can be obtained when the friction moment from substrate balances the driving moment from DNs. Results also demonstrated that, at temperature lower than 100 K, stronger compression from DNs will introduce larger SRF to the flake due to stronger driving force from the DNs. Under the same conditions, a smaller flake has higher SRF. When changing the layout angles of DNs in a range with width of ~90°, both the SRF and rotational direction of the nanoflake change monotonously. These characteristics suggest a clue for design of a nano-stirrer with controllable rotation for potential applications, e.g., separation and purification or generating nanoflow field through the gigahertz rotary flake.