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Prediction of manufacturing equipment’s energy consumption plays an important role in selecting appropriate process parameters for energy saving. However, it is difficult to model the energy consumption of metal forming equipment during the drawing process characterized by variable process parameters and dynamic loads. In this paper, a model was developed to quantify the energy consumption of a typical hydraulic press during the drawing process under a range of operating conditions. The hydraulic press studied consists of two different circuits and two controllable parameters, i.e., punch velocity and blank holder force can be set for drawing processes performed. To start, the energy flow during the drawing process was analyzed by using the energy conversion mechanism and components’ specifications to understand the detailed energy characteristics of each circuit. Then, orthogonal experiments including these two parameters at three levels were designed and carried out to find significant parameters. Finally, the contribution of each parameter, which was obtained from the analysis of variance (ANOVA) of the experimental results, was used to simplify energy flow modeling efforts. Consequently, a model of the press was established and used to predict the energy consumption of the drawing processes with different parameters. Good agreement with the experimental results was observed. The model can be used to identify parameters for minimal energy consumption, while the approach could be adapted to develop an energy consumption model for different hydraulic equipment.

Osteo-conductive bone substitute materials are required in dentistry. In this study, highly pressed nano-hydroxyapatite/collagen (P-nHAP/COL) composites were formed by a hydraulic press. Critical-size bone defects (Φ = 6 mm) were made in the cranial bones of 10-week-old Wistar rats, in which P-nHAP/COL and pressed collagen (P-COL) specimens were implanted. Defect-only samples (DEF) were also prepared. After the rats had been nourished for 3 days, 4 weeks, or 8 weeks, ossification of the cranial defects of the rats was evaluated by micro-computed tomography (micro-CT) (n = 6 each). Animals were sacrificed at 8 weeks, followed by histological examination. On micro-CT, the opacity of the defect significantly increased with time after P-nHAP/COL implantation (between 3 days and 8 weeks, p < 0.05) due to active bone regeneration. In contrast, with P-COL and DEF, the opacity increased only slightly with time after implantation, indicating sluggish bone regeneration. Histological inspections of the defect zone implanted with P-nHAP/COL indicated the adherence of multinucleated giant cells (osteoclasts) to the implant with phagocytosis and fragmentation of P-nHAP/COL, whereas active bone formation occurred nearby. Fluorescent double staining indicated dynamic bone-formation activities. P-nHAP/COL is strongly osteo-conductive and could serve as a useful novel bone substitute material for future dental implant treatments.

The automated evaluation of machine conditions is key for efficient maintenance planning. Data-driven methods have proven to enable the automated mapping of complex patterns in sensor data to the health state of a system. However, generalizable approaches for the development of such solutions in the framework of industrial applications are not established yet. In this contribution, a procedure is presented for the development of data-driven condition monitoring solutions for industrial hydraulics using supervised learning and neural networks. The proposed method involves feature extraction as well as feature selection and is applied on simulated data of a hydraulic press. Different steps of the development process are investigated regarding the design options and their efficacy in fault classification tasks. High classification accuracies could be achieved with the presented approach, whereas different faults are shown to require different configurations of the classification models.

With the growing cost of electrical energy, the necessity of energy-saving implementation in industries based on energy audits has become a major focus area. Energy audit results indicate energy-saving potential in an application and require the physical presence of the auditor’s team for monitoring and analyzing the energy consumption data. The use of Industrial Internet of Things (IIoT) for remote data monitoring and analysis is growing and new industrial applications based on IIoT are being developed and used by various industrial sectors. Possibilities of a mixed method of physical and remote energy audit using IIoT in industrial applications and its advantages as proposed in this research work needs to be explored. Existing hydraulic press machines running with direct online starter (DOL) can be run with variable speed drive (VSD) for energy saving but this requires an extensive energy audit. Key electrical and operational parameters of the hydraulic pump motor were monitored and analyzed remotely using IIoT in this research work by operating the hydraulic press with DOL and VSD motor control methods one by one. The input power factor of the hydraulic pump motor showed an improvement from 0.79 in DOL control to 0.9 in VSD control at different motor loads. The hydraulic pump motor starting current showed a reduction of 84% with VSD control. The hydraulic pump motor’s continuous current was reduced by 40% and 65% during the loading and unloading cycle, respectively, with VSD control. Electrical consumption was reduced by 24% as a result of operating the hydraulic pump motor at 35 Hz with VSD control without impacting the performance of the hydraulic press. These results indicated more efficient control by changing to VSD control in comparison with DOL control. A combination of physical and remote energy audits as performed in this research work using the proposed IIoT framework can be utilized for implementing energy saving in hydraulic presses thus motivating industries to adopt available more energy-efficient technologies at a faster pace.

The internal electro-hydraulic servo system of a hydraulic press is affected by the non-linear friction, and it becomes non-linear, unstable under vibration. In this study, the dynamic behavior and control of such a system were investigated. A mathematical model was first built and then proportional-integral-derivative control and sliding mode control were applied. Particle swarm optimization was used to find the optimal gain values and proportional-integral-derivative control parameters to control and stabilize the system. Sliding mode control was used for interactive comparison to demonstrate that the controller could avert chaos and restore stable periodic motion. A circuit was designed and assembled for the experimental confirmation of the results. The results showed that control of nonlinear behavior was better with sliding mode control than proportional-integral-derivative. This study can serve as a reference for the further investigation of hydraulic press electro-hydraulic servo systems.

The powder technology method was used for the purpose of making samples from the compound (Al-10%Al 2 O 3 -%WC), where the first support material was used alumina Al 2 O 3 at a fixed rate of 10% and the second support material WC was in different proportions (0,5, 10,15,20) %, the three powders were grinded together for a period of two hours, then put into a mold and the process was pressed with a hydraulic press at 5 tons for a time of one minute. An English-origin oven was used and the sintering process was done for the samples at 560°C and for a time of only two hours. After that, compositional tests (XRD), physical (real and apparent density, real and apparent porosity) and mechanical (diagonal compressive strength) were performed on the sintered samples. As these tests gave encouraging results with almost distinctive characteristics at a ratio of mixing of 20% WC and thermal sintering of 560°C, as the bulk density was within the limits of 5.51 g/cm 3 while the real density was 4.9 g/cm 3 , while the minimum apparent porosity was 8.83% and the porosity. The real one is 11.76%, while the diagonal compressive strength is 45.33MPa. As for the structural results of the X-ray diffraction after the sintering process, it showed the emergence of a new phase of the tertiary metal oxide (WO 3 ) and the (Triclinic) phase, as well as the emergence of tungsten carbide in the cubic phase.

This study focuses on realistic modeling of forming load and microstructural evolution during hot metal extrusion, emphasizing the effects of friction models and hydraulic press behavior. Rather than merely predicting load magnitudes, the objective is to replicate actual press operation by integrating a load limit response into finite element modeling (FEM). By applying Coulomb and shear friction models under both constant and hydraulically controlled press conditions, the resulting impact on grain size evolution during deformation is examined. The hydraulic press simulation features a maximum load threshold that dynamically reduces die velocity once the limit is reached, unlike constant presses that sustain velocity regardless of load. P91 steel is used as the material system, and the predicted grain size is validated against experimentally measured data. Incorporating hydraulic control into FEM improves the representativeness of simulation results for industrial-scale extrusion, enhancing microstructural prediction accuracy, and ensuring forming process reliability.

Large energy consumption caused by the pump unloading, as well as the low energy efficiency of the motor, is a serious problem for hydraulic presses especially for the press with multi motor-pumps. By analyzing the energy dissipation characteristic of hydraulic press drive system which is composed of several motor-pumps used to provide energy, an energy-saving design method is developed to reduce the energy loss of the drive system. In this method, pumps are selected from the pump set by minimizing the proposed idling index to reduce the energy loss of motor-pumps in the unloading state. The index is defined as the sum of the product of the unloaded flow and the unloaded time for each stage in a working cycle of the hydraulic press. Then, the motors are selected from the motor set to drive the selected pumps correspondingly by ensuring that the load rate of all the motors is within a setting range for high energy efficiency in as many stages as possible. The method was applied to a 2000-ton rapid sheet tension hydraulic press, and results indicate that 26.97% of energy can be saved in a working cycle.

This work aims to study four parameters that influence the compressive strength of compressed earth blocks (CEB): clay mineralogy, grain size, formatting pressure, and water content. Five soils with different mineralogical composition were used to study the first parameter. 12.5, 25, 40 and 60% of aggregates sized 0/2, 0/4 and 0/6.3 mm were added to the soil to study the second parameter. CEB were compacted at 100, 200 and 300 kN to study the third parameter. 3, 6 and 10% of water were used to study the fourth parameter. Test specimens were produced using a hydraulic press and characterized by compression. The characterization of the specimens shows that the compressive strength increases with the smectite content. Compressive strength does not always increase with changing particle size. Compressive strength increases with increasing formatting pressure, while increasing water content decreases compressive strength. This study also shows that the compressive strength of CEB is improved differently for each soil type.

This paper takes the position control performance of pump-controlled hydraulic presses as the research object. The control methods are designed respectively for the two motion stages of rapid descent and slow descent of hydraulic presses in order to improve the control performance of the system. First of all, the accuracy model of the pump-controlled hydraulic presses position servo system (the pump-controlled hydraulic presses position servo system, which is called PCHPS) and its MATLAB/Simulink simulation platform are established. Based on the theoretical analysis and experimental data, the interference factors affecting the tracking accuracy and positioning accuracy of the PCHPS are analyzed. Then, an adaptive integral robust control (the adaptive integral robust control, which is called AIRC) for PCHPS is designed to reduce the influence of nonlinear factors on the system, and the effectiveness of the controller is verified by simulation. Finally, the position control experiment of PCHPS is designed, and the experimental results show that the AIRC can effectively reduce nonlinear factors such as unknown interference in the slow-down stage of the system. The positioning accuracy is raised to within 0.008 mm, which improves the process level of the hydraulic presses.