In this study, the effects of print parameters on the mechanical properties of additively manufactured metallic parts were investigated using a tensile test. The 17-4 PH stainless steel specimens ...with two print parameters, including infill density and pattern orientation, were fabricated by additive manufacturing (AM) using the bound metal deposition (BMD) technique. The mechanical properties considered in this study are the Young's modulus and ultimate tensile strength. The results demonstrate that the pattern orientations do not affect the Young's modulus of the infill specimen with the triangular pattern. In contrast, the ultimate strength significantly varies depending on the pattern orientations, where the samples with the pattern orientation of zero degrees yield the best ultimate strength. In fact, the mechanical properties of infill specimens increase with their infill density. However, when operating cost and time are considered, an index for estimating performance and sustainability is consequently established. The relationship between the normalized ultimate strength of an infill specimen and the relative density is defined as the weight efficiency. The index for assessing a sustainable product is characterized by the weight efficiency versus sustainable parameter(s). The index can help end users select an appropriate infill density for AM products by considering the operating cost and time. Different cost models, including material-only costs, direct costs, and total costs, can be included in the index model to assess a sustainable product in a particular cost context.
The transport sector accounts for massive global CO2 emissions. To achieve low-carbon transport systems, promoting electric vehicles (EVs) is a crucial strategy of worldwide countries. Since the ...current rapid growth of EVs, the total cost of ownership (TCO) of EVs has been studied among countries promoting EVs in their transport sector. This study presents TCO models of EVs compared to a conventional internal combustion engine (ICE) vehicle. The EVs considered in this study include a hybrid electric vehicle (HEV), a plug-in hybrid vehicle (PHEV), and a battery electric vehicle (BEV). The cost models consist of capital and operating costs, i.e., depreciation, maintenance, tax, insurance, loan interest, battery, and energy consumption costs. All data are obtained from real-world testing in Thailand. The TCO models are analyzed based on the average distance traveled, 20,000 km/year for over 15 years driving in urban areas. The results show that the TCO of ICE, HEV, PHEV, and BEV is 61.19, 54.94, 55.94, and 60.89 (1,000 USD), respectively. The lifetime TCO ratio for each holding year is also proposed. The HEV and PHEV seem to be suitable choices without any BEV support policies in Thailand. Additionally, using the TCO models and presenting as a 15-year lifetime TCO ratio, two case scenarios of different EV support policies are assumed, i.e., a government subsidy, or a retailer discount and battery price discount. Direct support towards the vehicles’ purchasing prices significantly decreases the TCO. The knowledge from this study could be helpful for consumers, manufacturer product planners, and government policymakers.
Electric vehicles (EVs) are broadly admired as an encouraging solution to decarbonize and relieve air pollution in metropolitan transportation. However, each powertrain gives different benefits ...depending on the actual usage context. This study investigates the energy consumption of various EVs compared to a conventional internal combustion engine (ICE) vehicle. The considered EVs include a hybrid electric vehicle (HEV), plug-in hybrid vehicle (PHEV), and battery electric vehicle (BEV). Different road characteristics in the biggest city of northern Thailand are tested as driving route modes, i.e., city, rural, and hill modes, to study the energy consumption of the powertrains under real-world driving scenarios. Additionally, the efficiency of the CO2 emission reduction of each powertrain, analyzed from the energy consumption, is presented through the Well-to-Wheel (WtW) basis. The results show that the BEV performs well with all route characteristics, while both hybrids are appropriate in different driving scenarios. On average, of all the route modes, the WtW CO2 emission of the HEV, PHEV, and BEV is about 65%, 50%, and 35%, respectively, compared to the ICE. The BEV only has WtT CO2 emission from its electricity source. Therefore, it can yield low emissions if renewable energy, such as solar or wind energy, is used as its electricity source instead of fossil fuels.
Currently, metal additive manufacturing (MAM) has been receiving more attention in many sectors for its production of metal parts because MAM effortlessly enables the fabrication of complex metal ...parts and provides faster and more sustainable manufacturing than conventional processes. Recently, a MAM-using bound metal deposition (BMD) has been proposed as a user-friendly manufacturing method that can provide low-volume production, economical metal parts, and operation safety. Since the BMD technique is new, information on the mechanical properties of MAM parts using this technique has not been sufficiently provided. This paper aims to study the mechanical properties of MAM parts manufactured by the BMD technique, examining the elastic modulus, yield strength, ultimate strength, and fatigue behavior of the parts with different relative densities. The MAM parts made from 316L and 17-4PH stainless steel were investigated using tensile and fatigue tests. Some mechanical properties of the infill parts in this study were validated with formulas from the literature. The weight efficiency is used as an index to assess the efficiency of the infill parts with different densities by examining the relationship between the mechanical properties and the weight of the MAM parts. The experimental results and a discussion of the weight efficiency assessment are presented as a novel information report on MAM products fabricated by BMD technology.
The transportation industry is undergoing a major shift towards electrification to mitigate carbon emissions and decrease reliance on fossil fuels in response to global climate change and greenhouse ...gas concerns. Recently, battery electric vehicles (BEVs) have made significant progress and are becoming a more viable option for achieving zero-emission transportation. The aim of this study is to investigate the energy consumption patterns of BEVs operating in real-world driving scenarios encompassing various route conditions. The vehicle sensor data employed in this study was acquired through onboard diagnostic devices that directly gathered raw data and subsequently transmitted it to mobile applications. Various significant factors, such as payload, road slope level, speed range, acceleration, and loads of heating, ventilation, and air conditioning, are considered as variables influencing energy consumption. By utilizing the large amount of data collected, machine learning (ML) techniques were applied to develop a predictive model of energy consumption and identify variables that influence energy consumption. The outcomes of this study hold the potential to offer guidance to transportation policymakers and furnish valuable insights for prospective buyers considering BEVs. Furthermore, the application of ML in the development of a predictive model demonstrated efficacy and exhibits promising potential for wider-ranging applications.
Global carbon dioxide (CO2) emissions have continuously grown over the past decade. In recent years, nations worldwide have encouraged the use of electric vehicles to reduce the use of fossil fuels ...in the global transportation sector. To encourage people to transition to electric vehicles, the total cost of ownership (TCO) is the main focus of devising appropriate incentives or subsidies. However, most TCOs emphasize the expenses an owner must incur, regardless of the hidden cost that society must pay. Consequently, the social cost of carbon plays a significant role in the assessment of the losses from the point of view of society. This study reveals the social cost over the lifetime of electric vehicles (EVs), compared to an internal combustion engine vehicle (ICEV). In this study, the energy consumption of the considered vehicles was obtained from a real-world driving test. The CO2 emissions from energy consumption and battery production are evaluated. The social cost model was developed based on the CO2 emissions. A sensitivity analysis validates the social cost model via case scenarios by considering assumptions and conditions suitable for Thailand’s context. The social cost model can be applied with the TCO model for government policymakers and manufacturer planners to estimate the appropriate subsidy to incentivize EV buyers and minimize the social costs.
The development of rubberwood into electricity generation for biomass power plant is one of the most interested renewable energy options in Southern part of Thailand. This research presents a biomass ...supply chain for power generation is Southern part of Thailand focusing on only rubberwood in Southern region including three border provinces and the survey on one rubberwood power plant. The results show that the remaining potential of biomass from rubberwood in three border provinces for electricity generation is approximately 40.2 MW and the amount of biomass in other provinces within the radius of 200-km, 187.62 MW is remaining. Therefore, only 40.2 MW remaining potential for NEW power plant in three border provinces from rubberwood, more rubberwood needs to be imported from other provinces. The policy recommendation from this research is import the rubberwood from other provinces or long-term contract with supplier.
This paper aims to analyze the plastic collapse moment of circumferential cracked cylinder under pure torsion using the NSC approach and 3D FE model. The material considered in this work is assumed ...to be elastic-perfectly plastic. The influences of geometric parameters of crack and cylinder, such as R
m
/t, a/t and θ/π on solution of plastic collapse load are also investigated. The analysis shows that for the case of a/t < 0.75, the values of limit torsion moment can be estimated by NSC analysis which provides conservative results. However, for the case of deeper crack, a/t ≥ 0.75, the limit load solution predicted by NSC approach may not be safe, because the distribution of stress at yielding state does not correspond to the NSC assumption. Therefore, the approximated solution of collapse torsion moment for the case of deeper crack with a/t ≥ 0.75 is proposed based on FE analysis.
Cylinder is one of the most commonly used components which has a risk of having circumferential cracks, especially in the welding zone. When cracks are discovered, it is necessary to perform the ...failure strength assessment of cracked cylinder and the limit load play an important part as the input of the assessment. At present, the limit load solution for circumferential cracked cylinder under combined bending and torsion can be estimated by using the methods of equivalent moment or biaxial failure parameter. However, these methods still have some limitations. The main aim of this paper is to propose the alternative method for predicting the failure moment of circumferential cracked cylinder under combined bending and torsion. The method used in this paper is based on the modification of biaxial failure parameter and the data from finite element analysis. Details of this method is presented in this paper.
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