Case Study on Numerical Calculation of a Disc Bush in the Disc Harrow in the Welding Version

The optimization of production processes in companies comes down to two main measures influencing the economic factor. The first one is the reduction of interval micro-periods between operations, and the second is to use post-production waste as much as possible. These treatments apply to virtually all industries regardless of the final product effect. This article describes the application of a special welding device for welding the workpiece with a bush type, designed for fixing the plate in the plate gun. As a result of its application, a significant reduction of time needed to produce one bush has been achieved, and thus the amount of time in a unit of time has been increased. As part of the implementation work, the bush design changes were also made, which made it possible to reduce post-production waste not suitable for current production, but allowing its use for other purposes. The results of the work were implemented in the company producing agricultural machinery in Lublin.

On the Influence of Electrical Discharge Drilling Parameters and Per-formance Measures of Inconel 718 Superalloy - a Study

In order to achieve higher productivity and product quality, the investigation of machining parameters on Electrical Discharge Drilling and surface characteristic analysis are most critical for manufacturing industries. The intention of this article is to assess the impact on performance matrices including Material Removal Rate, and Surface Roughness of input factors of peak current, pulse-on and off duration while drilling with a rotary hollow copper tool on Inconel 718 under Tungsten powder suspended kerosene. Analysis of Variance has been implemented using MINITAB release 18 software to identify the most significant input factors. An Artificial Neural Network was used for validating the experimental results of the drilling process. The additional intention of this research is to discover the significance of influencing input parameters and analyze the quality surface of the workpiece were observed by microscope tests. The experimental results indicated that the peak current and pulse-on period have an effect on the performance of the drilling process considerably.

Application of Finite Element Sub-modeling Techniques in Structural Mechanics

Sub-modeling techniques implemented in commercial finite element codes were reviewed. New sub-modeling applications in structural mechanics stress analysis are presented. Sub-modeling methods based on displacement and force cut boundary application are compared. Advantages and disadvantages of these methods are discussed. The case of nested sub-models is demonstrated.

Fractional Calculus Control of Road Vehicle Lateral Stability after a Tire Blowout

The lateral stability control of the vehicle can avoid serious traffic accidents when it had a tire blowout during the operation. This article proposes a robust nonlinear control method for controlling vehicle lateral stability after a tire blowout. To be exact, a seven degree of freedom dynamic model of vehicle with modified Dugoff tire model is established. The yaw moment of vehicle is performed by differential braking once the tire blowout occurring. As for control strategy, taking the linear two degree of freedom vehicle model as the reference, using the deviation of yaw rate and the vehicle side angle between the actual value and the reference value as the controller input parameters, the fractional calculus theory is utilized for yaw moment controller which was investigated by regulating the brake moment of blowout vehicle for improving its stability. The results of computer simulation show that the design controller of fractional PID can more effectively enhance the blowout vehicle performance stability compared with the vehicle with the non control, PID control, no matter in straight road or curve road.

Catalyst Conversion Rates Measurement on Engine Fueled with Compressed Natural Gas (CNG) Using Different Operating Temperatures

Further restrictions on the use of compression-ignition engines in transportation are prompting the search for adaptations to run on other fuels. One of the most popular alternative fuels is Compressed Natural Gas (CNG), which due to its low carbon content can be competitive with classical fuels. This paper presents the results of testing a Cummins 6BT compression ignition engine that has undergone numerous modifications to convert to CNG power. The sequential gas injection system and the ignition system were installed in this engine. The compression ratio was also lowered from 16.5 to 11.5 by replacing the pistons. Tests conducted on an engine dynamometer were to show the differences in emission and conversion in the catalyst of hydrocarbons contained in the exhaust gases. Two structurally different catalysts operating at different exhaust temperatures (400 and 500)±2.5°C were used. The catalyst operating at 500±2.5°C showed a 23.5% higher conversion rate than the catalyst operating at a lower temperature in the range of the speed range tested. Also the external indicators, such as power and torque for the case of higher operating temperature took values over 70% higher. The research is one of the stages of a comprehensive assessment of the possibility of adaptation of compression ignition engines to CNG-only fueling.

Material Parameters Identification for Modelling of Carbon Rod Structures Delamination

The aim of the present work is to compare the interlaminar shear strength and fracture toughness of glued carbon fiber rods obtained using different experimental approaches and provide the effective way to characterise the interlaminar properties for reliable simulation of the delamination. Five different test methods (tension, single shear test, and double shear test, mode I and mode II delamination tests) were performed. Using the explicit LS-DYNA code the finite element model capable of simulating the damage process of bonded connection was developed. The interlaminar connection and delamination criteria were calibrated using the parameter identification methodology implemented in LS-OPT optimization tool.

Measurement of The Cycloidal Drive Sleeves and Pins

In the paper, an issue of CMM measurement strategy of the sleeves and pins designed for wear tests in the cycloidal drive. The measurement strategy was proposed, based on initial out-of-roundness measurement in scanning mode. Proposed approach ensured that the pin was measured along its entire 40 mm length with only small area of fixation ca. 5 mm left out, and all probing points for cylindricity deviation assessment were collected in one fixation. It was demonstrated that the cylindricity and roundness measurement results based on 8, 16 and 48 probing points provided sufficient data for further wear analysis. In some cases, the circles calculated from 4 points gave additional insights allowing to accept the part that otherwise might be possibly rejected.

Research on Three-point Bending Mechanical Performance of Square Tube Structure Filled with Foam Aluminum

In this paper, the quasi-static three-point bending experiments are carried out to study the deformation behavior of square tube and square tube filled with foam aluminum. The difference of bending deformation mode, loading characteristics and energy absorption efficiency between tube and foam aluminum filled tube is compared. And the influence of adhesive between the foam aluminum core and the tube wall on the bending deformation of square tube filled with foam aluminum is analyzed. Based on the bending super beam element model of tube structure, the relationship between the moment and rotation of square tube filled with foam aluminum under transverse static loading is analyzed. And the formula for calculating the moment and rotation angle of square tube filled with foam aluminum at three-point bending is obtained. In order to compare the simulation results, theoretical calculation results and experimental results of quasi-static bending, the three-point bending deformation of square tube and filled with foam aluminum under quasi-static and impact loading is simulated by finite element method. The results show that the filling of foam aluminum can improve the bearing capacity and energy absorption performance of the square tube structure. Under the bending load, the deformation degree of the bearing section is greatly reduced, which increases the bearing capacity of the structure and increases the stability of its bending resistance.

An Improved Dynamic Boundary Condition in SPH Method

Dynamic boundary condition (DBC) has been widely used in SPH method. However, in certain situations, it was found that a few fluid particles could break through the boundary or were not reflected specularly. Of course, these phenomena are unphysical. To improve the performance of DBC, an improved dynamic boundary condition (IDBC) was presented in this paper. To prevent fluid particles from breaking through the boundary, the repulsive force of boundary particles was enhanced by expanding the equation of state into a higher order. To deal with the asymmetry of DBC, a rectangular support domain attached to boundary particles and a corresponding correction factor are proposed. The results of three test cases showed that the performance of IDBC was satisfied.

Study of Flow Pressure Characteristics of Improved Rotary Valve

This work was supported in part by The National Natural Science Fund of China, Scientific research fund of Nanjing Institute of Technology, Open fund project of Anhui University of Technology, Practical innovation project of graduate students in Jiangsu Province. Support Fund Nos. 51505211, 11302097, CKJB201901, HVC202004, SJCX20_0700.