Quality control is considered a critical aspect of plastic materials in the injection molding process. Two types of deformations occur during the injection molding process, namely, volumetric shrinkage and warpage. This study aims to optimize the warpage of the polyethylene terephthalate preform (PET) used for the packing of carbonated drinks. PET warpage results in an uneven distribution of material over the wall surface of the preform and causes variation in wall thickness. During the filling operation of carbonated drinks, the preforms are subjected to high pressure at the points where the wall thickness is at a minimum, which induces a high-stress concentration. Under high pressure, the preforms are ruptured at the points where the warpage is at a maximum (stress concentration area), causing wastage of the beverage as well as the preform. In this study, the Taguchi method and analysis of variance (ANOVA) are used to determine the most significant parameters to induce warpage during the molding process. Then, we optimize the process parameters in order to reduce warpage through a numerical approach using SolidWorks Plastics. The result shows that the ambient temperature and melting temperature are the most critical parameters that contribute to the warpage, yielding 42.115% and 41.278%, respectively. Among the 6 parameters considered for this study, the pressure holding time contributes a minimum of 0.5961% to the yielding of the warpage. Overall, by optimizing the process parameters, warpage of the PET preform is minimized by 7.7202%, which helps to reduce wastage of the carbonated drink as well as the rejection rate of the preform during the filling operation. In a nutshell, the quality of the preform is improved.

As to the aircraft, structure, airborne equipments and aero-engine are of paramount importance. PHM (Prognostics and Health Management) implementation can help the aviation industry to significantly improve safety standard. The basic principles, the motivation of PHM and the key technologies involve sensing technology, fault diagnostic technology and prognostic methods are reviewed firstly in this paper, then the specific PHM application for structure, airborne equipments and aero-engines are presented in detail. Thirdly, the exiting integrated PHM systems and the relevant maintenance management systems from different company are explored, respectively. Lastly, PHM applications in Chinese aviation industry are discussed.

The binary nitride coatings corresponding to Ti, Zr, Nb, Mo, and Ta have good thermal stability, hardening wear resistance, and high-temperature oxidation resistance. Therefore, the high-entropy alloy nitride coating composed of these five elements is expected to show excellent mechanical properties, and it is suitable for extending tool life in dry-cutting environments. In this paper, (TiZrNbMoTa)Nx high-entropy nitride films were synthesized using a multitarget nonequilibrium magnetron sputtering technique. The paper aimed at investigating the effects of different nitrogen flow rates (FN) on the microstructure and mechanical properties of the films. The results show that, with the increase in FN, the deposition rate gradually decreased, the films exhibited a face-centered cubic structure, and the grain gradually changed from coarse columnar crystals to ultrafine grain structures. The hardness, elastic modulus, and binding force all showed a tendency to increase and then decreased with increasing FN. The hardness and elastic modulus reached their maximum values of 34.39 and 400.97 GPa, respectively, at an FN of 60 SCCM, and the formation of covalent bonds and grain refinement promoted the increase in hardness. This research provided a theoretical foundation for designing and preparing high-entropy ceramic coatings with high performance.

Clamping bushing structure is an internode connection mechanism designed for the standard section of tubular truss tower. In this paper, the clamping bushing structure of the connecting mechanism of super-large tower crane is taken as the research object, a three-dimensional model of clamping bushing structure is established and imported into ABAQUS, and its multi-body contact model is further constructed to study the contact and bearing relationship of the structure under multiple working conditions, and the accuracy of the calculation results of the model is verified by the experimental stress test under tensile working conditions. In addition, this study is based on the control variable method, and through the design of orthogonal test table, the influence degree of five variable parameters of clamping bushing on the bearing capacity of the structure is investigated. Finally, through the range analysis, the optimal horizontal combination of variables and parameters of clamping bushing structure is obtained, and the optimal matching relationship between the shape of the tower connecting mechanism and the bearing capacity is obtained. The results show that, compared with the original model, the stress concentration at the most dangerous section of the optimized joint and the bushing is obviously alleviated, in which the stress peaks of the upper and lower joints are kept below 500 MPa, and the stress peaks of the bushing groove are also reduced to between 573 and 722 MPa. Moreover, the designed and optimized lower joint can reduce the maximum equivalent plastic strain of the joint root circumference by 56.05% under the original maximum tensile condition, and the overall distribution trend of equivalent plastic strain is more uniform, and a more reliable structural design is obtained, which plays an important guiding role in the design, optimization and analysis of the connecting mechanism of the tower body of large tower crane.

In process optimization, a process is adjusted so as to optimize a set of parameters while meeting constraints, with the objective to either minimize the total processing time or maximize the throughput. This article focused on the process optimization of a fully automated yogurt and flavor-filling machine developed based on the industrial revolution 4.0 concept. Mathematical models were developed for minimizing the total processing time or maximizing the throughput of an Industry 4.0-based yogurt filling system with two different machine settings called Case-I and Case-II. In Case-I, the yogurt and flavors are filled at two distinct points while Case-II considers the filling of yogurt and flavors at a single point. The models were tested with real data and the results revealed that Case-II is faster than Case-I in processing a set of customer orders. The results were used as inputs for the single-dimension rules to check which one results in more intended outputs. Additionally, different performance measures were considered and the one with most importance to the management was selected.