Plastic Parts Research Articles

Integrating Taguchi Method and Gray Relational Analysis for Auto Locks by Using Multiobjective Design in Computer-Aided Engineering

In automobiles, lock parts are matched with inserts, and this is a crucial quality standard for the dimensional accuracy of the molding. This study employed moldflow analysis to explore the influence of various injection molding process parameters on the warpage deformation. Deformation of the plastic part is caused by the nonuniform product temperature distribution in the manufacturing process. Furthermore, improper parameter design leads to substantial warpage and deformation. The Taguchi robust design method and gray correlation analysis were used to optimize the process parameters. Multiobjective quality analysis was performed for achieving a uniform temperature distribution and reducing the warpage deformation to obtain the optimal injection molding process parameters. Subsequently, three water cooling system designs—original cooling, U-shaped cooling, and conformal cooling—were tested to modify the temperature distribution and reduce the warpage. Taguchi gray correlation analysis revealed that the main influencing parameter was the mold temperature followed by the holding pressure. Moreover, the results indicated that the conformal cooling system improved the average temperature distribution.

A CDM-like constitutive law for predicting degradation of strength and ductility of steel subjected to cyclic loading

This paper presents a continuum-damage-model-like constitutive law embedding cohesive cracks with plasticity-induced damage to represent the degradation of strength and ductility of steel under cyclic loading. The proposed constitutive law accommodates an arbitrary hyperelasticity-based plastic model with the use of the deformation gradient multiplicatively decomposed into separation-induced, elastic and plastic parts, and incorporated with an additional isotropic hardening rule endowed with a memory surface. While the elastic–plastic deformation along with isotropic and kinematic hardening is represented by a Hencky-type model, the separation-induced deformation gradient due to material separation is employed to embed an arbitrary cohesive traction separation law (CTSL) into the hyperelasticity-based plastic model. Also, a plasticity-induced damage variable is added to the selected CTSL to degrade the critical energy release rate. In addition, a new material constant is introduced to adjust the ratio between the critical values of cohesive traction and material separation width in the CTSL. On the other hand, the additional hardening rule depending on memory surface is appended in conjunction with the conventional isotropic and kinematic hardening rules to reflect the difference in plastic deformation with various ranges of cyclic loading. Several experiments are conducted to identify the material parameters and verify the validity of the proposed model. By reference to the experimental results, the capability of our proposed constitutive law is demonstrated in predicting the degradation of tensile strength and breaking elongation of a steel after cyclic loading.

Marine litter on sandy beaches with different human uses and waste management along the Gulf of Nicoya, Costa Rica

This study was a baseline with quantitative data of marine litter along the Gulf of Nicoya, Costa Rica. The objective of the study was to quantify marine litter and its association with human activities in this estuarine gulf. A total of fourteen sandy beaches were cataloged by the degree of urbanization, tourism intensity, beach cleaning programs, and tributary rivers as possible drivers of marine litter presence. The items of the marine litter were separated and weighted by type. Analysis by the clean coastal index (CCI) and multivariate statistics were applied to find spatial patterns in marine litter in the gulf. On beaches with the highest touristic activity, cigarette butts and straws were the main components. Locations with river plume influence, less frequent cleanup, or waste cans showed more bottles, plastic parts, and sanitary waste than beaches in other conditions. A beach in a fisherman town had recently utilized plastic bags, household goods, and boat parts in the marine litter. A wildlife refuge beach showed only small plastic and coffee foam cup fragments that came with currents from other points in the estuary. River basin management, solid waste disposal programs, and environmental education to avoid single-use items combined with correct waste disposal are needed to reduce marine litter in tropical countries focused on ecological tourism.

Double Scalar Variables Plastic-Damage Model for Concrete

A framework of the plastic-damage model with double scalar variables is established in nominal stress space under the small deformation assumption. In the damaged part, a damage tensor composed of double scalar variables is presented to comprehensively characterize the isotropic damage behavior in three-dimensional (3D) conditions. The damage laws of Young’s modulus and shear modulus are proposed to capture their different damage characteristic observed in the test. For one-dimensional (1D) and 3D conditions, the applicability of single scalar and double scalar damage variables is discussed. The macroscopic damage difference between these two damage variables when describing damage under 3D conditions is analyzed. In the plastic part, the plastic strain increment is determined by two parts of magnitude and direction. The magnitude is obtained by the consistency condition, and the flow direction is defined by the nonorthogonal flow rule that can satisfactorily reproduce the dilatancy behavior of concrete. The proposed model is implemented by the explicit Runge–Kutta (RK) method with the fifth-order accuracy and the Pegasus method. The performance of the model is assessed by the comparison results between the model and the cyclic loading and unloading test data under different stress paths.

Mechatronic module design of the control system for the tractor gearbox

This article describes the mechatronic control device for the manual gearbox system and points out disadvantages of the transmission controls located in the operator’s cab. The block diagram of the gearbox control unit is presented. The choice of the device elements is proved. PETG plastic part models of the mechatronic module printed on a 3D printer are proposed. The technical characteristics of the mechatronic module of the gearbox control system for the transport and technological vehicle are described.

STUDY OF TECHNOLOGY OF PRODUCTION OF SLAP PARTS FROM PLASTIC MATERIALS WORKING IN OIL-MINING EQUIPMENT

This article is devoted to the study of the technology of preparation of smooth parts prepared of plastic materials working in oil-field equipment. The strengh of smooth part sin oil-field equipment,the collection of plastic parts, as well as complex properties are studied. Due to the fact that the components of plastic materials have high performance indicators,the usual processing methods are used by preparing them in various constructions. This shows that in the chemical environment,the items prepared of plastic materilas are electrically conductive,heat-resistant additives. This problem is especially important in the use of structures made of plastic materilas,which are widely used in oilfield equipment,and parts made of diferent types of heterogeneous materials.Their quality is formed in the process of design and construction. Ensuring the quality of components made of thermoplastic and thermosetting material sin the production process can be considered a topical issue.If we look at the pros and cons of the plastic materials quality management sector: It is possible to point out to the interested parties whether the existence of processing facilities has not been initiated for collection and segregation. On the downside, the existing standarts do not meet internaitonal standards and we can note that there are technological problems. Plastic materials are superior to metal sin many respects. Their quality indicators,the accuracy,strengh,level of cleanliness,ensure reliability and durability. The production and acquisition of new types of plastic mass is in the focus of attention of many research centers in the world’s leading countries. Soviet scientists were the first to invert endless screwredcers made of plastic. These examples are 10 times cheaper than in previous years, and 5-6 times light. For example, in Russia Karajoyev plastic plant, Lyubucevsk plastic plant, etc. such as large plastic plants are currently operating. Currently, the industry cannot be imagined without plastic mass. We can call the twentieth century the polymer century. The appliciation of plastic materials of plastic materials has many advantages in industry. For example,duet o its low weight and thermal and electrical conductivity,it is used in industries in developed countires. They also have high static and dynamic properties. The advantage of the dynamic feature is the application of plastic material sin areas such as radio engineering and electrical engineering. Examples of areas where smooth parts made of plastics are applied include machine building, aviation, petrochemistry, missile technology and instrument making. Smooth parts made of plastic materials have high reliability, durability and longevity.İn developed countiries, 40-50 percent of the materials used in mechanical engineering,instrument making and other industries are plastics of various brands,Plastics are easy to-process,low-cost and durable parts. Smooth parts made of plastics have high reliability, durability and longevity. The article analyzes the operation of plastic mass components,the analysis of the technology of production of smooth parts made of plastic materials used in oilfield equipment,as well as their strengh and reliability. Keywords: Plastic material, quality indicators, thermoset materials, performance indicators.

Accidental or intentional ingestion of toothbrushes: experience with 8 adult patients.

Ingestion of a toothbrush is an unusual event but may occur either accident or by intent. Radiological examinations play a crucial role in determining the exact location of the object within the gastrointestinal tract and in planning for its removal by endoscopic or surgical intervention. Medical and radiological records of 8 patients who had swallowed the broken heads or entire toothbrush were retrospectively reviewed. This series included 4 men and 4 women, ranging in age from 21 to 57 years (mean: 34 years). Radiographs and computed tomography of the abdomen demonstrated the ingested toothbrushes within the stomach in 3, lodged in the duodenum in 1, and entrapped in various parts of the colon in 4 patients. They were removed by laparotomy in 3, laparoscopy in 2, colonoscopy in 2, and upper gastrointestinal endoscopy in 1 patient. There were no perforations or associated complications, and all patients had uneventful recoveries. Ingested toothbrushes can be easily identified on radiological studies because of the radiopaque wires holding the nylon bristles. The plastic parts of it, however, are only visible on computed tomography. All cases would require endoscopic or surgical removal of the retained toothbrushes because spontaneous passage per rectum does not occur.

Optimization of Injection Molding of Automotive Plastic Horn Cover Part Using Taguchi Method and Reverse Engineering

The aim of the paper consisted in the development of an injection mold for plastic horn cover parts in commercial vehicles. Three mold types were designed in anticipation of the structure and quality of molds, and injection molding numerical analyses were conducted for the three types of molds. One mold type was selected in consideration of the resin flow patterns inside the mold, surface quality, and final deflection amount of the horn cover. To perform optimal injection molding using the selected mold, optimization of injection molding parameters was performed using the Taguchi method, one of the designs of experiment (DOE) and ANOVA methods. As a result, it was confirmed that the deflection amount of the molding under optimal molding parameters decreased by about 34.3% compared to the deflection amount before optimization of the molding parameters. Based on these encouraging results, the previously selected mold type was actually manufactured. The horn cover was molded using the obtained optimal injection molding parameters to the manufactured mold. To verify the precision of the molded horn cover, the deflection amount of the molding was measured with a 3D scanner. The deflection amount of the horn cover was estimated to be about 11% to 43% larger for each measurement position than the deflection amounts in the analysis results. The manufactured mold was revised to solve the problem that the deflection amount of the actual molding is larger than the deflection amount predicted by injection molding analysis. The dimensions and surface quality of the horn cover with a revised mold were satisfactory.

Phase-field implicit material point method with the convected particle domain interpolation for brittle–ductile failure transition in geomaterials involving finite deformation

A phase-field implicit material point method with the convected particle domain interpolation (PF-ICPDI) is proposed to model the brittle–ductile failure transition in pressure-sensitive geomaterials involving finite deformation. In this method, the phase-field fracture formulation relying on the microforce balance law and the second law of thermodynamics is adopted as a nonlocal damage function for the elastoplastic fracture analysis. A smooth two-yield-surface plasticity constitutive model is utilized to evaluate the brittle–ductile failure transition behavior of pressure-sensitive geomaterials. The coupling effect of phase-field fracture model and cap plasticity model is established by introducing an effective phase-field stress and splitting the total stored energy into elastic and plastic parts. The implicit material point method that can avoid severe mesh distortion and improve numerical stability is then developed to solve the quasi-static elastoplastic fracture finite deformation problem. Furthermore, the convected particle domain interpolation technique is adopted to eliminate numerical noises and improve computational accuracy while material points crossing cell boundaries in modeling the large deformation brittle–ductile failure transition process. The staggered incremental iterative scheme is carried out to solve the coupled discrete governing equations. The accuracy and capability of the proposed PF-ICPDI method are demonstrated through several representative numerical examples, as well as the effects of main material parameters on the phase-field brittle–ductile failure transition modeling of geomaterials are discussed.

Mechanical properties of metal and polymeric viscoelastic materials and their applications

Nowadays, With the wide application of metals and polymeric materials, how to describe the property of Viscoelastic material and how to apply them in engineering has become more and more critical. Due to the lack of insight into the mechanical properties of viscoelastic materials, many scholars have done a lot of experiments in studying the behavior of viscoelastic materials. Axial tensile tests were conducted on specimens to derive different mechanical behaviors of metals, polymers, and other materials at different temperatures and loading rates. Metal can generally be divided into elastic and plastic parts, while polymeric materials have the phases of the linear elastic region, drawing region, and oriented molecular strength region. This paper also shows a test conducted by Argon, Ali S., and M. I. Bessonov of four different kinds of polymers at different circumstances of temperature. After that, the paper shows the application of viscoelastic materials as CLD in damping and some engineering problems caused by the mechanical properties of viscoelastic materials. Currently, research on viscoelasticity should mainly focus on the application of Finite Element Methods and the acquisition of more experimental data to establish a complete theoretical system.

The Prediction of Cracking Load and Peak Load of UHPC‐NC Composite Structure

In this study, models for calculating the cracking load and a peak load of the UHPC‐NC structures are established. The effects of UHPC's high tensile strength, reinforced steel bars in NC, reinforce steel bars in UHPC, and prestress tendons in UHPC on cracking load and peak load are considered. In the cracking load model, UHPC is considered to be elastic and the stress distribution is triangular, the stress of steel bars and prestressing tendons is also calculated according to the plane section assumption and elastic theory. In the peak load module, UHPC is assumed to be partially elastic and partially plastic. The plastic part is represented by a rectangular stress block diagram, and the stress value reduction factor and rectangular stress frame height reduction factor are obtained by trial calculation. Compared with the experimental data of UHPC‐NC beams with different types of combinations collected from references, the calculated results have a high matching degree, which is suitable for various types of UHPC‐NC, both cracking loads and peak loads.

Совершенствование конструкции прототипа промышленного экзоскелета с использованием инновационных технологий

The work is devoted to the study and improvement of the design efficiency of industrial exoskeletons. Such devices are needed to perform the work that requires high physical activity in various production processes. To determine the optimal design, the developments of foreign and domestic markets were studied. It was revealed that the exoskeleton developed by Karfidov Lab LLC has the highest performance characteristics compared to the analogues. However, this design lacks a convenient saddle attachment system to support the user, and the exoskeleton is heavy — 6 kg. The authors proposed the modernization of the design of an industrial exoskeleton for the lower extremities. Modernization is associated with the use of solutions aimed at reducing the weight of the exoskeleton, as well as improving ergonomics by developing a saddle for each leg of the exoskeleton and a user fixation system. For this purpose, a solid-state 3D model and design documentation for producing exoskeleton were developed in the SolidWorks environment. To reduce the weight of the exoskeleton, plastic parts were used. The exoskeleton provides support for the user body, made in the form of a vest, as well as a fixation system in the form of straps located on the foot, shin, and thigh. To ensure increased shock absorption with an active exoskeleton, a gas spring manufactured by Suspa, model Varilock EL2-111-79-600N, was installed. To increase the strength of plastic parts, the reinforcement method was used. A saddle is introduced that provides a soft contact between the user and the system in the active and passive positions of the exoskeleton. The main requirements for the modernized development were the low cost of the final product and the lightness of the overall mass of the structure.

Dynamic Light Settings as Data Augmentations for Automated Scratch Detection

The manufacture of plastic parts requires a rigorous visual examination of its production to avoid the shipment of some that would be defective to its customers. In an attempt to ease the detection of scratches on plastic parts, the prototype of a computer-assisted visual inspection system was developed. The aim of this paper is to introduce how we explored ways to design a semi-automatic system comprising of a lamp whose orientations and intensities help in revealing irregularities on subjects that would have been missed with a unique light configuration. This process was qualified as “hardware data augmentation”. The pictures collected by our system were then used to train several convolutional neural networks (YOLOv4 algorithm/architecture). Finally, the performances of their models were confronted to evaluate the effects of the different light settings, and deduce which parameters are favourable to capture datasets leading to robust defect detection systems.

Development of Quadruped Robot TITAN-E1 Using Plastic Structural Parts Printed by Fused Deposition Modeling

Development of Quadruped Robot TITAN-E1 Using Plastic Structural Parts Printed by Fused Deposition Modeling

Optimization of injection molding process parameters based on GA-ELM-GA

The most common optimization method for the optimization of injection mold process parameters is range analysis, but there is often a nonlinear coupling relationship between injection molding process parameters and quality indicators. Therefore, it is difficult to find the optimal process combination in range analysis. In this article, a genetic algorithm optimized extreme learning machine network model (GA-ELM) combined with genetic algorithm (GA) was proposed to optimize the process parameters of the injection mold. Take the injection molding process parameter optimization of an electrical appliance buckle cover shell as an example. In order to find the process parameters corresponding to the minimum warpage deformation, an orthogonal experiment was designed and the results of the orthogonal experiment were analyzed. Then, the corresponding optimal process combination and the degree of influence of process parameters on the warpage deformation were obtained. At the same time, the extreme learning machine network model (GA-ELM) optimized by the genetic algorithm was used to predict the warpage deformation of the plastic part. The trained GA-ELM model can map non-linear coupling relationship between the five process parameters and the warpage deformation well. And the optimal process parameters in the trained GA-ELM network model was searched by the powerful optimization ability of genetic algorithm. Generally speaking, the warpage deformation after optimization by range analysis is reduced by 6.7% compared with the minimum warpage after optimization by orthogonal experiment. But compared to the minimum warpage deformation after orthogonal experiment optimization, the warpage deformation after GAELM-GA optimization is reduced by 22%, which is better than that of the range analysis, thus verifying the feasibility and the optimization of the optimization method. This optimization method provides a certain theoretical reference and technical support for the field involving the optimization of process parameters.

Vehicle Platform Effects on Performance of Flexible, Lightweight, and Dual-Band Antenna for Vehicular Communications

This paper highlights the impact of the ground, of the vehicle surroundings and of the car body on signal transmission and reception of a dual-band microwave antenna tested on two automotive plastic parts on a convertible vehicle for cellular and Cellular - Vehicle To Everything (C-V2X) communications. The implemented antenna operates at 975 MHz and 5.5 GHz and facilitates the future vehicular communications in vehicles without steady rooftops. Four experiments are performed with the antenna placed (a) in the Satimo near field system; (b) on a stanchion at an outdoor range facility without the presence of a car; (c) at the outdoor facility in the side mirror of the convertible vehicle; and (d) on the trunk lid of the same vehicle. Antenna co- and cross- polarization radiation patterns are measured and results indicate that the ground and the vehicle’s body affect the radiation performance of the antenna. The presence of ground causes an increase in the antenna’s cross-polarization level. The reflections caused by the car’s body perturb the omni-directional radiation pattern of the antenna and may degrade the vehicular microwave signal transmission due to the presence of nulls.

Closed-loop thickness control and sensor placement in extrusion blow moulding

Extrusion blow moulding (EBM) is a polymer forming technique used to manufacture hollow plastic parts, such as fuel tanks. In this work, the feasibility of using closed-loop control in EBM is explored to compensate for machine drift and disturbances. A control system is proposed to regulate the extrusion process in EBM. The extrusion controller aims to increase process consistency by minimizing part thickness deviations. The thickness of the extrudate is measured during the extrusion cycle and any deviation from the desired thickness profile is compensated by changing the die gap in real time. The controller, which offers flexibility in thickness sensor placement, features a Smith predictor configuration embedding an H∞ controller. It compensates for the input-dependent polymer transport delay, the nonlinear steady-state swell, and nonminimum phase necking effects affecting the extrudate. This extrusion control technique may help reduce the production rate of off-specification parts and improve product quality.

Adaption of the hole drilling method for residual stress analysis inside plastic parts

Residual stresses are a major factor in the production and use of parts. They arise mainly during the manufacturing process. Knowledge of residual stresses is a prerequisite, as they could have a detrimental effect. However, many known methods are only suitable for investigating near-surface regions. For the analysis of residual stresses within components, staggered machining has been developed. This paper deals with the principle and the experimental implementation of staggered machining. A suitable evaluation is performed and finally first results are presented.

Measurement of the Energy Absorbed during Nanoscale Deformation of Human Peritubular and Intertubular Dentin

Mineralized tissues are usually constructed of nanosized materials with ordered hierarchical structures. The main reason for their high load-bearing ability is the multi-scale hierarchy. It is important to have a method for measuring the energy absorbed during the nanoscale deformation of mineralized tissues. The objective of this study was to use a combination of nanoindentation and elastic-plastic mechanics techniques to measure the damage resistance of peritubular and intertubular dentin, based on the energy consumed in the plastic deformation regime and the volume created by the indents. The control materials were soda-lime glass, gold, and poly-methyl methacrylate (PMMA). Plastic deformation energy was calculated from the plastic part of load-displacement curves. The mean values of peritubular dentin and intertubular dentin were 3.8 × 109, and 5.2 × 109 J/m3, respectively, compared to glass, PMMA, and gold which were 3.3 × 107, 1.3 × 109, and 3.1 × 109 J/m3, respectively. This method can be applied to study the resistance of mineralized tissues or organic/inorganic hybrid materials to deformation at the nanoscale.

Elaboration and characterization of polymers used in flexible multilayer food packaging

Mechanical recycling is a major alternative for reducing the amount of fossil and natural resources needed to produce plastic materials. The process is essential when it comes to recycling multilayer plastic parts such as flexible food packaging. However, this recycling method generates a multiphase material whose interfaces must be stabilized so that it can be recovered. The nature of polymeric materials as well as their composition in flexible food packaging allows to achieve this, only if a chemical reaction is developed during the mixing stage (in-situ reaction). This work was the opportunity to demonstrate the potential of this strategy from model mixtures consisting of Linear Low Density Polyethylene (LLDPE)/ Ethylene Vinyl Alcohol copolymer (EVOH) and a commercial tie polymer called OREVAC. The latter is a linear low-density polyethylene-graft-maleic anhydride. In this work, two types of OREVAC were used (OR-PE 1 and OR-PE 2) as compatibilizers. The rheological and morphological results show the effect of the added compatibilizer, and the limited efficiency obtained due to the low quantity which has been used in the blends.