scholarly journals Redesign of the Geometry of Parts Produced from PBT Composite to Improve Their Operational Behavior

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2536
Author(s):  
Dan Dobrotă ◽  
Sergiu Viorel Lazăr
Keyword(s):  
Aging Process ◽  
Artificial Aging ◽  
Complex Shape ◽  
Design Method ◽  
Current Trend ◽  
Polybutylene Terephthalate ◽  
Injection Process ◽  
Car Safety ◽  
Safety Systems ◽  
Optimal Radius

Parts produced from PBT-GF30 (70% polybutylene terephthalate +30% fiberglass) are very often used in car construction, due to the properties of this material. The current trend is to make parts with a shape designed to be as complex as possible, to take over many functions in operation. During the research, a part that is a component of the structure of car safety systems, and that must be completely reliable in operation, was analyzed. This piece has a complex shape that involves the intersection of several walls. Thus, the research aimed at establishing the optimal radius of connection between the walls (R), the ratio between the thickness of the intersecting walls (K) and the angle of inclination of the walls (α). The composite central design method was used to design the experiments. Both new parts and parts subject to an artificial aging process were tested. All parts were subjected to shear stress, to determine the load (L) and displacement (D) at which they break. In order to observe other changes in the properties of the parts, in addition to the mechanical ones, an analysis of the color of the new and aged parts was performed, as well as a topography of the surface layer in the breaking area. The design of the parts involved changes to the parameters of the injection process. In these conditions, a PBT-GF30 viscosity analysis was performed for new and artificially aged parts.

scholarly journals A Shape Optimization Method for Part Design Derived from the Buildability Restrictions of the Directed Energy Deposition Additive Manufacturing Process

Designs ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 19
Author(s):  
Andreas K. Lianos ◽  
Harry Bikas ◽  
Panagiotis Stavropoulos
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Energy Deposition ◽  
Design Method ◽  
Current Trend ◽  
Internal Stresses ◽  
Material Distribution ◽  
Load Case ◽  
Design Elements ◽  
Industrial Sectors

The design methodologies and part shape algorithms for additive manufacturing (AM) are rapidly growing fields, proven to be of critical importance for the uptake of additive manufacturing of parts with enhanced performance in all major industrial sectors. The current trend for part design is a computationally driven approach where the parts are algorithmically morphed to meet the functional requirements with optimized performance in terms of material distribution. However, the manufacturability restrictions of AM processes are not considered at the primary design phases but at a later post-morphed stage of the part’s design. This paper proposes an AM design method to ensure: (1) optimized material distribution based on the load case and (2) the part’s manufacturability. The buildability restrictions from the direct energy deposition (DED) AM technology were used as input to the AM shaping algorithm to grant high AM manufacturability. The first step of this work was to define the term of AM manufacturability, its effect on AM production, and to propose a framework to estimate the quantified value of AM manufacturability for the given part design. Moreover, an AM design method is proposed, based on the developed internal stresses of the build volume for the load case. Stress tensors are used for the determination of the build orientation and as input for the part morphing. A top-down mesoscale geometric optimization is used to realize the AM part design. The DED Design for Additive Manufacturing (DfAM) rules are used to delimitate the morphing of the part, representing at the same time the freeform mindset of the AM technology. The morphed shape of the part is optimized in terms of topology and AM manufacturability. The topology optimization and AM manufacturability indicator (TMI) is introduced to screen the percentage of design elements that serve topology optimization and the ones that serve AM manufacturability. In the end, a case study for proof of concept is realized.

Investigation on the Stress Relaxation Aging Behavior of 2195 Al-Li Alloy

2021 ◽  
Vol 315 ◽  
pp. 37-42
Author(s):  
Hai Long Liao ◽  
Li Hua Zhan ◽  
Yuan Gao ◽  
Xue Ying Chen ◽  
Ming Hui Huang
Keyword(s):  
Mechanical Properties ◽  
Stress Relaxation ◽  
High Performance ◽  
Aging Process ◽  
Artificial Aging ◽  
Ageing Time ◽  
High Strength ◽  
Aging Behavior ◽  
Stress Corrosion Resistance ◽  
Scanning Electron

2195 Al-Li alloy is famous for high strength, excellent fatigue strength and good stress corrosion resistance, which is widely used in the manufacture of high-performance aerospace components. The aim of this study is to validate how the stress relaxation aging behavior effect on the mechanical properties of 2195 Al-Li alloy. Through mechanical property test, the research was found that the performance after stress relaxation aging is higher than artificial aging (AA). In addition, the analysis of scanning electron microscopy SEM and TEM revealed that dislocations should be introduced by the stress relaxation aging process, which is more conducive to the precipitation of the T1 phase and strengthened the material with prolong ageing time. The results show that stress relaxation aging can significantly promote the precipitation of the T1. Therefore, this paper sheds new light on how SRA can improve mechanical properties and that SRA make better improve the distribution of precipitates in the grain boundary.

scholarly journals Effects of Pre-Stretching on Creep Behavior, Mechanical Property and Microstructure in Creep Aging of Al-Cu-Li Alloy

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 333 ◽  
Author(s):  
Jin Zhang ◽  
Zhen Jiang ◽  
Fushun Xu ◽  
Mingan Chen
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Dislocation Density ◽  
Creep Behavior ◽  
Aging Process ◽  
Artificial Aging ◽  
Dislocation Motion ◽  
Nucleation And Growth ◽  
Blocking Effect ◽  
Creep Stage

The effects of pre-stretching on creep behavior, mechanical properties and microstructure during the creep aging process of Al-Cu-Li alloy were investigated. AA2195 was taken as the representative of Al-Cu-Li alloys. It is found that the total creep strain and strength property of creep aged AA2195 specimens can be improved through effective pre-stretching. Unlike with artificial aging, yield strength increased increasing by 47%. The TEM images show that the constitution of aging precipitates in the creep-aged specimens are obviously changed by pre-stretching. Precipitates in the 2% pre-stretched specimen are mainly composed of T1 phase, while a great amount of θ’ phase accompanied with a few T1 phase were found in the non-pre-stretched specimen. Moreover, pre-stretching introduces many dislocations which benefit the creep deformation, but the increasing dislocation density also accelerates the nucleation and growth of the precipitates as well. The premature T1 phase has a great blocking effect to the dislocation motion, creating a lower decrease rate but a longer duration in the early creep stage. Except for the initial dislocations, the dislocation motion in the creep aging process is also a favorable factor to precipitate the T1 phase.

Design of layered structure for thermal cloak with complex shape

2016 ◽  
Vol 30 (20) ◽  
pp. 1650256 ◽  
Author(s):  
Xuebo Yuan ◽  
Guochang Lin ◽  
Youshan Wang
Keyword(s):  
Numerical Simulations ◽  
Layered Structure ◽  
Complex Shape ◽  
Thermal Protection ◽  
Design Method ◽  
Two Dimensional ◽  
Spatial Transformation ◽  
Complex Shapes ◽  
Potential Applications ◽  
Thermal Cloaking

Thermal cloaks have potential applications in thermal protection and sensing, and those cloaks with complex shapes are much more efficient in application. Layered discretization is a valid way to realize thermal cloaks designed through spatial transformation which are usually nonhomogeneous and anisotropic. However, previous studies are limited to two-dimensional cylindrical ones. Based on the theories of spatial transformation and effective medium, a four-step design method for layered structure of thermal cloak with complex shape is proposed. It is expected to realize the designed layered structure by utilizing the existing regular materials. According to the numerical simulations, the thermal cloaking performances of layered structures are good and close to that of the perfect thermal cloaks. This study has provided an effective way for realizing thermal cloak with complex shape.

Effect of Artificial Aging Process on Aluminum Foam Made of Etial 160

2020 ◽  
Vol 73 (11) ◽  
pp. 2739-2745
Author(s):  
Lütfiye Dahil ◽  
Ramazan Katirci ◽  
Halil İbrahim Sümbül
Keyword(s):  
Aging Process ◽  
Artificial Aging ◽  
Aluminum Foam

Contaminant release from aged microplastic

2017 ◽  
Vol 14 (6) ◽  
pp. 394 ◽  
Author(s):  
Nicole Bandow ◽  
Verena Will ◽  
Volker Wachtendorf ◽  
Franz-Georg Simon
Keyword(s):  
Material Properties ◽  
High Density Polyethylene ◽  
Aging Process ◽  
Artificial Aging ◽  
Degradation Products ◽  
Total Content ◽  
Oxidation Reactions ◽  
Inorganic Species ◽  
Aging Conditions ◽  
Contaminant Release

Environmental contextIncreasing global plastic production adds plastic debris to the environment. We show that potentially harmful additives present in plastic particles are released to water at an increased rate when material properties change by aging due to exposure to high temperature and especially to UV radiation. For risk assessment of such plastic additives, more information on their degradation products and their toxicity is needed. AbstractRecycled plastic granules of high-density polyethylene, polyvinyl chloride and polystyrene the size of microplastics were exposed to artificial aging conditions (2000h; photooxidative and thermo-oxidative) to simulate their fate outdoors. Their potential to leach into water during the aging process was investigated using column percolation tests. Aging-related changes on the surface of the material were characterised by IR measurements indicating oxidation reactions with the formation of new adsorption bands (C=O, C–O and OH), especially in the case of photooxidative aging. These findings were confirmed by the identification of leachable organic compounds. Leaching of total organic carbon, Cl, Ca, Cu and Zn is clearly affected by changes due to aging, and their release is increased after photooxidative aging. In general, exposure to photooxidative conditions shows a greater influence on aging and thus on leaching and seems to be the more important mechanism for the aging of microplastic in the environment. Comparison with the total content of inorganic species revealed that, for most elements, less than 3% of the total content is released after 2000h of photooxidative aging.

Process Optimization of Mid-Density Tungsten Alloy for Injection Process in Metal Injection Molding Based on Numerical Simulation

2009 ◽  
Vol 628-629 ◽  
pp. 599-604
Author(s):  
Zhen Xing Zheng ◽  
Yuan Biao Wu ◽  
Wei Xia ◽  
Wei Ping Chen
Keyword(s):  
Numerical Simulation ◽  
Design Method ◽  
Pairwise Interaction ◽  
Fractional Factorial ◽  
Metal Injection Molding ◽  
Tungsten Alloy ◽  
Process Conditions ◽  
Single Factor ◽  
Injection Process ◽  
Moulding Machine

In this paper, based on the CAE technology for MIM and fractional factorial design method, the simulation for the filling process was executed in different process conditions by the Moldflow software. And then it was realized that the extent of the effects of the single factor and pairwise interaction between the process parameters on quality of green parts were forecasted. According to that, the relationships of pressure, velocity and time and their optimal combination were researched by the experiments using a FC-80 plastic-Injection-Moulding machine. The experimental results suggested that the pressure, velocity and time have a obvious pairwise interaction which can have more effect on the product than single factor. It was shown that there was a good consistency between the numerical simulation and experiment. The CAE technique and the experiments are combined to optimize the process conditions and improve the part quality automatically by using smaller number of experiments.

In-Car Safety Systems for Pedestrian and Cyclist Safety

ATZ worldwide ◽  
2013 ◽  
Vol 115 (10) ◽  
pp. 10-15
Author(s):  
Stefanie de Hair-Buijssen ◽  
Carmen Rodarius ◽  
Margriet van Schijndel-de Nooij ◽  
Rikard Fredriksson
Keyword(s):  
Car Safety ◽  
Safety Systems

Design and Manufacturing of Air Conditioner Panel Hot Runner Injection Mold Based on CAD/CAE/CAM

2010 ◽  
Vol 42 ◽  
pp. 68-72 ◽  
Author(s):  
Zhi Gang Jin ◽  
Wu Ji Jiang ◽  
Min Xia Yu
Keyword(s):  
Design Method ◽  
Mold Design ◽  
Injection Mold ◽  
Air Conditioner ◽  
Whole Process ◽  
Injection Process ◽  
Nc Programming ◽  
Machine Module ◽  
The Cost ◽  
Design And Manufacture

Take air conditioner panel for example, it is introduced that the whole process of hot runner injection mold design and manufacture based on CAD/CAE/CAM technology. The panel structure and injection process were analyzed using HuaSu CAE software, then the panel structure was designed using UG/Mold Wizard software, the NC programming and manufacture simulating of the formed parts were done by UG/MACHINE module at last. Compared with the traditional mold design method, CAD/CAE/CAM technology not only can improve the efficiency, shorten production period, but also can reduce the cost of mold design and manufacture greatly.

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