Total Traction Research Articles

Use of wide-width tractor units in cotton growing

Abstract The article provides information on recommended traction and power balances of a cotton tractor used in sowing and cultivating 8 rows in growing of cotton seeded at 60 cm row spacing. The purpose of the research is to solve problem of aggregation of sowing and cotton cultivators with four-wheeled tractors and increase their operational-technological and technical-economic performance. According to it, conditions for aggregation of processing units with a tractor are given. The results of scientific and practical research and testing to determine and evaluate performance of machine-tractor units consisting of inter row spacing sowing and cultivators with four-wheel tractors were obtained and analyzed. The dynamics of a tractor in which all bridges are leading and moving forward at a constant speed along a sloping plane are studied. The result is traction balance equation that represents the total traction force of tractor. In particular, the issue of selection and rational aggregation of a tractor model that can be rationally aggregated with a Case-1200 pneumatic seeder has been resolved. It is determined the range of changes the traction resistance and power required to overcome it, the operating weight of tractor, mass and effective power of the Case-1200 seeder.

Single-stage correction of severe scoliosis with syringomyelia: performed with traction assistance without prophylactic neurosurgical decompression.

There is still controversy about whether it is necessary to perform prophylactic neurosurgical decompression for severe scoliosis (SS) with syringomyelia (SM) to reduce the risk of neurological complications during subsequent spinal correction. This study aimed to explore the safety and effectiveness of using traction-assisted single-stage spinal correction as a treatment for patients who had SS with SM (SS-SM). The patients who had SS-SM without previous neurosurgical intervention and who underwent traction-assisted single-stage posterior spinal correction at a single center were included, and the initial, posttraction, and postoperative clinical data were reviewed. Based on preoperative MRI, the included patients were divided into two categories: those with versus those without Chiari malformation type I (CM-I-related SM [CS] vs idiopathic SM [IS]), and those with a moderate syrinx (MS) versus those with a large syrinx (LS). Different groups' traction and operation contributions were calculated for comparisons (CS vs IS, MS vs LS). A total of 28 patients were included. The initial mean major scoliosis was 101.0° with a mean flexibility of 21.4%. After the operation, the mean total correction rate for scoliosis was 63.9%. The mean traction and operation contributions were 61.5% and 38.5%, respectively. Most of the patients (75%) underwent spinal corrections without 3-column osteotomies, and only 1 patient reported postoperative regional numbness without motor deficits. No differences were found in the mean total correction rates, traction, and operation contributions when comparing CS versus IS and MS versus LS with the comparable initial clinical data (p > 0.05). More than 50% of the total corrections were achieved by preoperative traction in all groups. Traction-assisted single-stage spinal correction can safely and effectively correct SS-SM without prophylactic neurosurgical decompression under strict patient selection. Additionally, traction can achieve more than half of the final spinal correction, even for patients with varying sizes of SMs.

Vertical vibration of a rigid disc over a transversely isotropic and layered poroelastic half-space

A novel semi-analytical method is proposed for solving the vertical vibration of a rigid disc over a transversely isotropic and layered poroelastic half-space. The fundamental solutions in the layered poroelastic half-space under a vertical patch load on the surface are solved in terms of the newly developed Fourier-Bessel series (FBS) system of vector functions and the unconditionally stable dual-variable and position method. The expansion coefficients in FBS system are discrete, as such the computational efficiency is greatly improved and the accuracy is better than the commonly used integral-transform methods. By virtue of the superposition method, the Green’s function due to vertical ring load is derived in the transform domain. By making use of the integral least-square scheme, the densities of a series of ring loads discretized within the disc area are determined. Finally, the dynamic vertical compliance is derived via the balance between the external applied force and the induced total contact traction. After verifying the reliability of the developed solution, selected numerical examples are presented to investigate the influence of material properties and excitation frequency on the forced vibration of the rigid disc.

The efficacy of gradual reduction using two-stage traction for developmental dysplasia of the hip in southern China.

This study aimed to report the preliminary outcome of gradual reduction (GR) utilizing two-stage traction (TST) compared with traditional traction (TT) in the treatment of developmental dysplasia of the hip (DDH) and to evaluate whether the prognosis of the TST is better than that of TT. The following information on children diagnosed with DDH who underwent treatment with GR using two-stage traction or traditional traction between June 2016 and August 2017 was collected: sex, age, weight, acetabular index (AI), International Hip Dysplasia Institute (IHDI) classification, femoral head ossification, traction time, reduction quality, and labrum shape in arthrography. The AI, IHDI classification, second operation rate, and incidence of femoral head avascular necrosis (AVN) were analyzed after the final comprehensive 1-year follow-up. In this study, 27 cases (31 hips: 18 left and 13 right) were enrolled, with 18 hips (16 cases) assigned to the TT group and 13 hips (11 cases) assigned to the TST group, with the corresponding average age at diagnosis of 5.56 ± 1.66 and 4.06 ± 1 months (p < 0.001). For both TT and TST groups, the average age at operation was 6.01 ± 1.67 and 65 ± 0.86 months (p = 0.435), the distribution of affected left and right sides was 10/8 and 8/5 hips (p = 1), and the average initial AI was 37.11 ± 3.26 and 36.77 ± 4.34 (p = 0.804), respectively. IHDI classification III/IV was observed in 15/3 and 11/2 hips, respectively (p = 1). Femoral head ossification was present in 6/18 hips in the TT group and 2/13 hips in the TT group (p = 0.412). The total traction time was 13.22 ± 2.6 days for the TT group and 49.23 ± 25.77 days for the TST group (p < 0.001). After GR, IHDI classification III/IV was observed in 9/9 and 12/1 hips, respectively (p = 0.02). AVN was present in 5/18 hips in the TT group and 0/13 hips in the TST group (p = 0.048), while the need for a second operation was approved in 5/18 hips in the TT group and 1/13 hips in the TST group (p = 0.359) at the final follow-up. Two-stage traction can significantly decrease the ratios of IHDI classifications III and IV and the incidence of AVN compared to traditional traction; also, it significantly reduces the total traction time.

Efficient and reliable divergence-conforming methods for an elasticity-poroelasticity interface problem

We present a finite element discretization to model the interaction between a poroelastic structure and an elastic medium. The consolidation problem considers fully coupled deformations across an interface, ensuring continuity of displacement and total traction, as well as no-flux for the fluid phase. Our formulation of the poroelasticity equations incorporates displacement, fluid pressure, and total pressure, while the elasticity equations adopt a displacement-pressure formulation. Notably, the transmission conditions at the interface are enforced without the need for Lagrange multipliers. We demonstrate the stability and convergence of the divergence-conforming finite element method across various polynomial degrees. The a priori error bounds remain robust, even when considering large variations in intricate model parameters such as Lamé constants, permeability, and storativity coefficient. To enhance computational efficiency and reliability, we develop residual-based a posteriori error estimators that are independent of the aforementioned coefficients. Additionally, we devise parameter-robust and optimal block diagonal preconditioners. Through numerical examples, including adaptive scenarios, we illustrate the scheme's properties such as convergence and parameter robustness.

ECHILIBRAREA MOTOARELOR ELECTRICE DE TRACȚIUNE PENTRU COMPENSAREA EFECTELOR TRANSFERULUI DE SARCINĂ

The individual drive of the axles of a vehicle produces a reduction of the axle adhesion, implicitly reducing the total traction force of the vehicle. The paper proposes eliminating load transfer effects by using an algorithm to redistribute the traction effort between the tractive axles equipped with electric traction motors. A case study is presented, using the balancing of the electric traction torque for an electric locomotive, using the load transfer effects compensation. The conclusions can be extended to maximise the traction of all types of vehicles, such as trailers, hybrid tractors, large harvesters, and Diesel-electric locomotives.

Calculating some Powers and Traction Force for Two Plows in Primary Tillage

Traction force and power requirement when performing primary tillage occupy the minds of almost farmers, this field research had aim to determine and calculate the pulling force of the most commonly used moldboard and chisel plows, the research conducted in silt clay loam for chisel and moldboard plows as the main factor, two depths of tillage 18 and 25 cm as a second factor and three speeds of tractor 2.55, 4.30 and 6.15 km.h-1 as a third factor. Moldboard plow recorded least traction force 7.550 kN, drawbar power 11.583 hp, power losses due to slippage 1.088 hp, power on the rear axle of the tractor 15.770 hp and brake horse power 17.495 hp. Chisel plow recorded best traction efficiency 76.217 % and total traction efficiency 68.659 %. Depth of tillage 18 cm recorded least traction force 7.837 kN, drawbar power 12.190 hp, power losses due to slippage 0.986 hp. Speed tractor 2.55 km.h-1 recorded least traction force 8.246 kN, drawbar power 7.329 hp, power losses due to slippage 0.618 hp, resistance power losses due to motion 1.775 hp and power on the rear axle of tractor 9.723 hp. Correlation among performance indicators were positive and negative correlation significantly, also were insignificant correlation.

18p Deletion Syndrome With Concurrent Frizzled-4 Mutation: Surgical Management of Bilateral Stage 5 Traction Retinal Detachment.

We report a case of a patient with 18p deletion syndrome and concurrent FZD4 (frizzled-4) mutation. A 6-month-old boy with known 18p deletion syndrome presented with abnormal eye movements in both eyes and an inability to track objects. The patient had a history of laryngomalacia, hypotonia, and developmental delay. Examination showed bilateral total exudative and traction retinal detachment with anomalous retinal vascular development noted on widefield fluorescein angiography. Genetic analysis identified a concurrent FZD4 mutation (c.205C>T [p.H69Y]). Both eyes underwent 25-gauge limbal vitrectomy, lensectomy, and membrane peeling, and the posterior pole successfully reattached with improvement in visual function. The 18p region contains the LAMA1, TGIF1, and APCDD1 genes, which are involved in the vascular basement membrane and Wnt/β-catenin signaling, which may have potentiated the particularly severe familial exudative vitreoretinopathy phenotype. We present the clinical findings, imaging analyses, and surgical management of concurrent 18p deletion syndrome and FDZ4 mutation. The overlap in molecular mechanisms of the multiple gene products may potentiate the severe phenotype. [Ophthalmic Surg Lasers Imaging Retina 2023;54:284-290.].

Collaborative Optimization Method for Multi-Train Energy-Saving Control with Urban Rail Transit Based on DRLDA Algorithm

With the traffic congestion problem deteriorating, people increasingly choose urban rail transit (URT) to travel. Although URT alleviates traffic congestion, the long-term operation of a large number of trains leads to huge energy consumption. In order to adapt the major social development concept of “Low carbon”, a multi-train energy-saving control collaborative optimization method is proposed in this paper. First, the composition of single train operating conditions is determined by the conversion of operating conditions between stations and the force changes under the premise of ensuring safe and on-time train operation. A single-train energy consumption calculation combinatorial optimization model with the dual control objectives of reducing passengers’ average waiting time as well as train traction energy consumption is established. The energy saving control strategy of a single train is investigated by ARMA-Radial Basis Function Neural Network (ARMA-RBFNN) and Genetic Algorithm (GA). Next, the queuing theory is introduced to analyze the variation in passenger waiting time for multiple trains at different arrival intervals. A Deep Reinforcement Learning (DRL) algorithm is designed to obtain the correlation among passenger waiting time, arrival interval and train stopping time. The optimization objective is to minimize the multi-train traction energy consumption and the average passenger waiting time while considering conditions such as train operating safety interval, speed limit, multiple operating state and single train energy-saving models, etc. Then, a multi-train cooperative energy-saving control model is proposed based on the Dragonfly Algorithm (DA). Finally, a case study of Beijing Metro Line 4 is conducted to illustrate the effectiveness of the proposed method. The results demonstrate that the total traction energy consumption and passenger waiting time are reduced by 3.1% and 5 s, respectively, compared with the method of independently optimizing the single-train control strategy. The findings can aid in the development of energy-saving strategies and also provide a basis for energy-saving operation control of multiple trains.

Impact of COVID-19 pneumonia on interstitial lung disease: semi-quantitative evaluation with computed tomography.

To evaluate the CT scores and fibrotic pattern changes in interstitial lung disease (ILD) patients, with and without previous COVID-19 pneumonia. Patients with ILD (idiopathic pulmonary fibrosis (IPF) and connective tissue disease-associated ILD (CTD-ILD)) were retrospectively enrolled in the study which consisted of patients who had COVID-19 pneumonia while the control group had not. All patients had two CT scans, initial and follow-up, which were evaluated semi-quantitatively for severity, extent, and total CT scores, fibrosis patterns, and traction bronchiectasis. A total of 102 patients (pneumonia group n = 48; control group n = 54) were enrolled in the study. For both groups, baseline characteristics were similar and CT scores were increased. While there was a 4.5 ± 4.6 point change in the total CT score of the COVID-19 group, there was a 1.2 ± 2.7 point change in the control group (p < 0.001). In the IPF subgroup, the change in total CT score was 7.0 points (95% CI: 4.1 to 9.9) in the COVID-19 group and 2.1 points (95% CI: 0.8 to 3.4) in the control group. Seven patients (14.6%) in the COVID-19 group progressed to a higher fibrosis pattern, but none in the control group. Semi-quantitative chest CT scores in ILD patients demonstrated a significant increase after having COVID-19 pneumonia compared to ILD patients who had not had COVID-19 pneumonia. The increase in CT scores was more prominent in the IPF subgroup. There was also a worsening in the fibrosis pattern in the COVID-19 group. • The impact of COVID-19 pneumonia on existing interstitial lung diseases and fibrosis is unclear. • COVID-19 pneumonia may worsen existing interstitial lung involvement with direct lung damage and indirect inflammatory effect. • COVID-19 pneumonia may affect existing lung fibrosis by triggering inflammatory pathways.

Inversion approach to grade computation of track drivers of hoisting and road machinery

Caterpillar movers is a widespread variant of implementing conveying mechanisms for lifting, construction and road vehicles, which has a number of advantages in comparison with rail-wheeled, pneumatic-wheeled and stepping mechanisms, in particular, it does not require working platforms and has improved driving qualities when moving over rough terrain. This paper proposes an inversion approach to the traction calculation of a tracked mover, which lies in representation of its traction and carrying elements in the form of a closed contour, which allows applying the basic provisions of the theory of traction calculation of continuous vehicles to determine the resistance to motion and, accordingly, the tension in the contour of the caterpillar belt. The proposed approach makes it possible to estimate the contribution of different motion resistances to the total traction force during the rectilinear motion depending on the design features of each specific area of the tracked belt taking into account the load redistribution between different caterpillars of one chassis. The obtained results can be applied both in designing conventional special tracked vehicles and in developing prototypes of caterpillar vehicles with displaced load application centers, in particular, caterpillar chassis of mobile transport-overloading rope complexes.

Temperature Effect on Load Distribution, Friction, and Wear of a Grease-Lubricated Spherical Roller Bearing (SRB)

This article investigates the effect of temperature on the lubrication and wear behavior of a grease-lubricated spherical roller bearing (SRB) assuming mixed-elastohydrodynamic lubrication (mixed-EHL) where the contact load is shared between the lubricant film and contact asperities. Temperature effects on internal load distribution and elastic modulus and their subsequent effect on the wear are also analyzed. The effect of temperature is investigated, first on the film thickness and load sharing, and then on the friction and wear. If the temperature rises from ambient to 110 °C, the increase in the contact patch dimensions, due to the decrease of elastic modulus, is only approximately 1% and the decrease in mean contact pressure is approximately 2%. Moreover, the load at decreases by approximately 4%, and the load zone increases by approximately 5%. As the temperature rises from 50 to 110 °C, the asperity portion of the contact load at position is increased by 350%. At 50 °C, only 20% of the total traction is contributed by the contact asperity, which is 80% at 110 °C. For the temperature rise from 50 to 110 °C, the wear volume loss increases by 238% and nonlinearly, due to viscosity reduction and its effect on the reduction of film thickness. The isolated change of internal load distribution and elastic modulus due to temperature rise causes a relatively insignificant change in wear. Hence, the predominant effect of temperature rise on wear is due to a decrease in lubricant film thickness causing the asperity component of the contact load to increase.

Real-Time Predictive Control of Path Following to Stabilize Autonomous Electric Vehicles Under Extreme Drive Conditions

A novel real-time predictive control strategy is proposed for path following (PF) and vehicle stability of autonomous electric vehicles under extreme drive conditions. The investigated vehicle configuration is a distributed drive electric vehicle, which allows to independently control the torques of each in-wheel motor (IWM) for superior stability, but bringing control complexities. The control-oriented model is established by the Magic Formula tire function and the single-track vehicle model. For PF and direct yaw moment control, the nonlinear model predictive control (NMPC) strategy is developed to minimize PF tracking error and stabilize vehicle, outputting front tires’ lateral force and external yaw moment. To mitigate the calculation burdens, the continuation/general minimal residual algorithm is proposed for real-time optimization in NMPC. The relaxation function method is adopted to handle the inequality constraints. To prevent vehicle instability and improve steering capacity, the lateral velocity differential of the vehicle is considered in phase plane analysis, and the novel stable bounds of lateral forces are developed and online applied in the proposed NMPC controller. Additionally, the Lyapunov-based constraint is proposed to guarantee the closed-loop stability for the PF issue, and sufficient conditions regarding recursive feasibility and closed-loop stability are provided analytically. The target lateral force is transformed as front steering angle command by the inversive tire model, and the external yaw moment and total traction torque are distributed as the torque commands of IWMs by optimization. The validations prove the effectiveness of the proposed strategy in improved steering capacity, desirable PF effects, vehicle stabilization, and real-time applicability.

Review on Integrated On-Board Charger-Traction Systems: V2G Topologies, Control Approaches, Standards and Power Density State-of-the-Art for Electric Vehicle

This article reviews the different topologies compatible with V2G feature and control approaches of integrated onboard charger (iOBC) systems for battery electric vehicles (BEVs). The integrated topologies are presented, analyzed, and compared in terms of component count, switching frequency, total harmonic distortion (THD), charging and traction efficiencies, controllability, reliability and multifunctionality. This paper also analyzes different control approaches for charging and traction modes. Moreover, the performance indices such as setting time, rise time, overshoot, etc., are summarized for charging and traction operations. Additionally, the feasibility of a Level 3 charging (AC fast charging with 400 Vac) of up to 44 kW iOBC is discussed in terms of converter efficiencies with different switching frequencies and switch technologies such as SiC and GaN. Finally, this paper explores the power density trends of different commercial integrated charging systems. The power density trend analysis could certainly help researchers and solution engineers in the automotive industry to select the suitable converter topology to achieve the projected power density.

TRACTION QUALITIES OF THE DRIVING WHEELS WHEN ROLLING THEM ALONG ONE TRACK

During rectilinear motion of a wheeled tractor on a deformable surface, its rear wheels move along the track formed by the front ones. The amount of soil compaction can be different depending on its physical and mechanical properties, the dimensions of the front wheels of the tractor, the weight load falling on the front axle, and the like. Accordingly, the traction abilities of the rear drive wheels will also be different. This circumstance should be taken into account when designing wheeled tractors, especially tractor-tractors with two driving axles, in which a change in any of the factors listed above, for example, the distribution of the load along the axles, affects not only the compaction of the surface on which the rear wheels move, but and on the traction qualities of the front. In the course of the research, it was found that with a decrease in the load distribution coefficient below 0.5, the role of the rear wheel, which is capable of developing a greater traction force than the front wheel at the same load, in the formation of the total traction force, decreases. Therefore, the total traction force of the driving wheels becomes lower. With an increase in this coefficient above 0.5, the amount of preliminary soil compaction by the front wheel decreases; as a result, the ability of the rear wheel to develop more traction than the front wheel under the same load is reduced. The greatest traction force of two driving wheels moving along the same track is achieved with the same weight loads. Thus, the position of the center of gravity of a tractor with four driving wheels of the same size should be chosen in such a way that the load on the front and rear wheels is equalized at the rated pull on the hook. When conducting research on a field prepared for sowing, with an active semi-trailer with different load distribution between the rear axle of the tractor and the axle of the semi-trailer, it was found that the center of gravity of the active semi-trailer can be selected in the same way as for the inactive one, i.e. taking into account the influence of the semi-trailer on traction performance. The dependences obtained in the work make it possible to analyze the traction qualities of several driving wheels when they roll along one track. With their help, it is possible to identify the effect of surface compaction on the traction qualities of the rear moving front wheels; the influence of load distribution along the axles of the driving wheels on their total traction force, etc.

Effects of combined adjustable Halo-pelvic fixation brace on cervical spine alignment in patients with severe rigid spinal deformity

ObjectiveTo evaluate the effect of continuous traction with a combined adjustable Halo-pelvic fixation brace on the cervical spine alignment in patients with severe rigid spinal deformity and analyze its related factors.MethodsWe conducted a retrospective cohort study of 21 patients with severe rigid spinal deformity treated in our department between 2015 and 2019. All subjects received combined adjustable Halo-pelvic fixation brace traction before secondary orthopedic surgery. The influence of the Halo-pelvic fixation brace on the cervical spine alignment was evaluated by measuring the parameters of lateral cervical X-ray at three time points: before traction, at the end of traction, and 6 months after orthopedic surgery. The correlation between parameter changes and total traction duration was analyzed to explore factors influencing cervical alignment.ResultsThe C2L-C7L angle was 22.40 ± 15.91° before traction, which decreased to 5.91 ± 6.78° at the end of traction but increased to 14.51 ± 10.07° after orthopedic surgery (BT vs ET p < 0.005, ET vs AOS p < 0.005, BT vs AOS p < 0.005). Accordingly, C2L-C7U angle, C2L-C6L angle, C2L-C6U angle, C2L-C5L angle, C7 or T1 slope, C2-C7 SVA, SCA, C2-T1 Ha, C0 slope, and C0-C2 angle also changed similarly to C2L-C7L angle. Furthermore, moderate correlation was observed between C2L-C7L angle and total traction volume (r = 0.563, p = 0.008) and SCA and traction duration (r = 0.525, p = 0.015). However, no significant correlation was found between other cervical alignment parameters and total traction volume and traction duration.ConclusionsThe continuous traction of a combined adjustable Halo-pelvic fixation brace can affect the cervical spine alignment of patients with severe rigid spinal deformity and straighten the physiological curvature of the cervical spine. However, the sagittal alignment gradually recovers after the traction, without any adverse effects on the orthopedic surgery and global balance after the operation; therefore, this apparatus is worthy of wide application.

Predicting the impact of intraoperative halo-femoral traction from preoperative imaging in neuromuscular scoliosis.

Intraoperative traction (ITx) has been demonstrated to be a useful adjunct intervention at the time of posterior spinal fusion (PSF) for the treatment of severe neuromuscular scoliosis (NMS) to improve the coronal spinal deformity and pelvic obliquity. The purpose of this study is to determine if preoperative flexibility radiographs can predict the amount of spinal deformity and pelvic obliquity correction at final follow-up. This was a retrospective analysis of a single-surgeon series who underwent PSF to the pelvis with adjunct ITx for NMS. Database query identified 76 NMS patients, of which 41 met inclusion criteria. Demographic, radiographic and operative data were analyzed. Of the 41 study patients, 56% (n = 23) were male and mean age at surgery was 13.6years. Mean follow-up of 4.1years (minimum follow-up 2years). 35 patients had cerebral palsy, 5 patients were syndromic, and 1 patient had myelomeningocele. The average preoperative weight was 35kg and all were wheelchair ambulators. Total traction applied on average was 49% of the preoperative body weight. Mean preoperative coronal deformity was 91° which improved to 43° at final follow-up (53% correction). Push-supine imaging had the strongest correlation to major coronal deformity outcome at final follow-up (r2 = 0.87, p ≤ 0.0001). Compared to push-supine imaging, there was a mean greater coronal deformity correction of 18 ± 10° (p ≤ 0.0001) at final follow-up. To predict the final coronal deformity, the regression equation was final Cobb angle = 1.13085 + preop push-supine Cobb angle × 0.68830. Mean preoperative pelvic obliquity was 34° which improved to 12° at final follow-up (65% correction). Push-supine imaging had the strongest correlation to pelvic obliquity outcome at final follow-up (r2 = 0.59, p = 0.0001). Compared to push-supine imaging, there was a mean greater pelvic obliquity correction of 3 ± 10° (p = 0.0857) at final follow-up. The regression equation was final POB = 6.42096 + preop push-supine POB × 0.36675. Mean preoperative kyphosis was 70° and 52° at final follow-up (26% correction). The results of this study demonstrated for preoperative planning that the push-supine flexibility radiograph is most predictive of the coronal deformity and of the pelvic obliquity correction. At final follow-up in this NMS population, there was a mean greater improvement of 18° for coronal deformity versus preoperative push-supine imaging and 3° for pelvic obliquity versus preoperative push-supine imaging. At the time of PSF, ITx is an effective adjunct technique to improve coronal deformity and POB for NMS producing 53% coronal correction, 65% POB correction, and 26% kyphosis correction. IV.

Theoretical Substantiation of the Traction Resistance of the Ridge Seeder

The analysis of the current state of the enterprises of the agro-industrial complex of Russia has shown that various energy-saving cultivation technologies of agricultural crops, including row crops on ridges, are being applied on a large scale. Mainly, such technologies imply a reduction in the number of technological operations performed, the replacement of sowing on pre-treated soil with sowing according to minimal technology or no-till at all. When implementing comb sowing of row crops, the problem of energy saving remains relevant. Keeping in mind the design features and the operation principle of tillage rollers, it can be stated that they are designed mainly for the destruction of soil lumps and compaction of soil on a flat field before or after sowing. There is a problem of high-quality rolling of soil ridges formed simultaneously with the sowing of row crops. (Research purpose) The research purpose is to substantiate the traction resistance of a roller aggregated with a combed roller theoretically. (Materials and methods) The algorithms used to assess the quality of the rollers are imperfect, for reliable justification of the optimization parameter, it is necessary to solve a number of issues, in particular, the methodology for determining the traction resistance of rollers designed for the final creation of soil ridges by simultaneous action of spherical disks and conical wheels on their sides. A skating roller has been developed for the finishing operation of forming a soil ridge with the required parameters and density simultaneously with sowing, the novelty of which is confirmed by patents of the Russian Federation No. 194330, No. 194348, No. 196712. (Results and discussion) The article presents the process of forming a soil ridge by a roller, and the justification of the traction resistance of a ridge drill roller. A vertical load artificially created by a spring additionally acts on the roller of the comb seeder, this load evenly spreads to the conical core and spherical disks of the roller. (Conclusions) The total traction resistance of the roller of the comb seeder is affected by the weight of the conical wheel, frame, additional spring compression load, the size of the rolling wheel and spherical discs, the speed of the roller, as well as the physical and mechanical properties of the soil.

Geometric, kinematic and dynamic parameters of the disc ripper

Introduction. The unit of continuous action for the formation of the underlying layer is designed to increase labour productivity in the construction of roads and other objects, for the construction of which it is necessary to remove the upper layer of soil. For loosening of soil in the unit used bit-like working bodies. Often, disc working bodies are used to cut the soil. Therefore, the expediency of using passive discs in road-building technical means, in particular, in the unit of continuous action for the formation of the underlying layer of highways, is of practical interest. Despite the large number of works, a detailed analysis of the operation of passive disks was not made. Therefore, in order to compare the energy costs for cutting the soil with passive discs and chisel-shaped working bodies, it is necessary to make a theoretical analysis of the operation of passive disks. Analysis of the energy costs of the disk ripper cannot be carried out without having the approximate values of its geometric, kinematic and dynamic parameters.The method of research. As part of a continuous unit to form the underlying layer of roads, each disc would be clamped with soil on both sides and carried out clamped cutting. Therefore, a disk ripper is adopted for analysis, aggregated with a separate energy device. On the basis of the constructive layout, rational geometric parameters of the disk ripper are revealed. The method of calculation of its kinematic and dynamic parameters is developed. In particular, the method of determining the weighted average circumferental velocity of the disk, the angular velocity of the disk and the circumferental velocity of the point on the edge of the disk blade is considered. The modes of cutting the soil by various parts of the disk are considered.Results. On the basis of the developed technique, the dependence of the minimum diameter of the disk on the depth of soil development was revealed. The moment of resistance of the soil to the rotation of the disks is calculated. The horizontal and vertical component of soil resistance to the front disc carrying out clamped cutting and subsequent discs carrying out semi-clamped cutting of the soil are determined. The necessary thrust force of the energy device for cutting the soil with a disk ripper and the dependence of the thrust force of the energy device for cutting the soil on the depth of soil development were revealed. The performance of the unit, including the power device and the disk ripper, is calculated.Conclusion. Since as part of the unit of continuous action for the formation of the underlying layer of roads, the disks will carry out clamped cutting of the soil, for preliminary loosening of the soil with disks, it is more expedient to use a separate unit, including an energy device and a disk ripper. On the basis of the theoretical studies carried out, the necessary thrust force of the energy device for cutting the soil and the total traction force necessary to move the disc ripper were revealed. The performance of the unit is calculated. To compare the energy costs for cutting the soil with passive discs and chisel-shaped working bodies, it is necessary to make a theoretical analysis of the energy costs for the operation of passive disks.

Impregnation modeling and preparation optimization of continuous glass fiber reinforced polylactic acid filament for 3D printing

AbstractContinuous glass fiber reinforced polylactic acid (CGF/PLA) composites were prepared by 3D printing technology in this study. The multi‐roll melt impregnation mold was manufactured according to the melt impregnation model. CGF/PLA filament was prepared by a melt impregnation device, and then used to prepare CGF/PLA composite materials by the self‐modified 3D printer device. The full impregnation of the fibers was achieved by the action of the coverage angle of the tension roller in the impregnation mold. The effects of the total coverage angle, traction speed, fiber content, and impregnation temperature on the fiber impregnation effect and 3D printed product performance were studied. The bending strength, tensile strength, impact strength, and interlayer shear strength of the printed sample reached 312, 220, 154, and 14 MPa, respectively. The strategy in this study can effectively improve the impregnation effect of PLA resin on CGFs and promote the development and application of 3D printing technology in the field of high‐performance composite manufacturing.