A.A. Nuraini

Decision making model for optimal reinforcement condition of natural fiber composites

Natural fiber reinforced polymer composites (NFCs) have recently received much attention as eco-friendly materials due to their desired characteristics such as the high specific properties, low cost, and recyclability features. Achieving an optimal reinforcement condition in NFCs to obtain desired properties is still challenging for both designers and industry. Selecting an appropriate reinforcement condition for natural fiber composites can dramatically enhance achieving better low-cost sustainable design possibilities. Several factors affect acquiring such reinforcement conditions, which make it a matter of multi-criteria decision making (MCDM) problem. This work was able to build and implement DM models in the field of NFCs to optimize the reinforcement conditions for the first time. Here, both Analytic Hierarchy Process (AHP) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) methods were utilized to achieve the optimal reinforcement condition of the date palm/epoxy composite to maximize its overall tensile property considering combined evaluation criteria. Eleven potential reinforcement conditions were evaluated regarding Maximum Tensile Strength (MTS), Maximum Shear Stress (MSS) and Elongation to Break (EL) criteria simultaneously. Experts’ feedback was surveyed to determine both the appropriateness of the evaluation criteria as well as their corresponding weights. MSS has the most contribution in the evaluation process with a weight of 39.0 %, whereas MTS and EL have weights of 31.0 % and 29.0 % respectively. The harmony between AHP and TOPSIS methods in determining the optimal reinforcement condition considering the whole desired evaluation criteria increased its reliability. This work presents a guide and roadmap for implementing proper decision making models in the field of natural fiber composites to optimize their desired characteristics as it is implemented here for the first time.

Predicting the potential of agro waste fibers for sustainable automotive industry using a decision making model

We developed a decision making model to rank natural fiber types for the first time.We predicted and ranked the potential of natural fibers for automotive industry.Flax and date palm fibers are the best choices from wide criteria standpoints.DPF is the best regarding many criteria like Fibers Specific Strength to Cost Ratio.DPF can promote productivity, sustainability and the environmental performance too. Developing a sustainable industry requires proper utilization of the available and compatible natural resources. Selecting a proper natural fiber type to form a reinforced polymer composite suitable for sustainable automotive industry is considered as a multi criteria decision making problem. This work (i) ranks different natural fiber types according to their appropriateness for the sustainable automotive industry using a decision making technique for the first time. (ii) Predicts the potential of the date palm fiber (DPF) as a reasonable cheap alternative for the sustainable automotive industry. A combined informative/expert-feedback decision making model utilizing the analytical hierarchy process (AHP) was built to rank and predict the potential of the natural fibers. This model can optimize finding the most appropriate available, cheap, eco-friendly alternative material to enhance not only the sustainability and productivity of the automotive industry but also the environmental performance too. A pilot questionnaire was conducted to ensure the appropriateness of the used model. The natural fiber options considered were: coir, date palm, flax, hemp and sisal. The flax fiber type is the best choice for automotive applications as it ranks highest, followed by the date palm fiber as a reasonable competitive cheap alternative choice. This decision was made based on simultaneous technical and economic standpoints. Date palm fiber was found to be the best choice regarding many criteria like Fibers Specific Strength to Cost Ratio one. Results demonstrated that the most AHP model priority stack was occupied by both Mechanical Properties and Specific Performance for Automotive Applications criteria. Sensitivity analysis illustrated the reliability of the results and the drawn judgments in this study.

A Model for Evaluating and Determining the Most Appropriate Polymer Matrix Type for Natural Fiber Composites

The process of determining the proper polymer matrix type, using a wide range of criteria, to form a natural fiber–reinforced polymer composite is still not established enough. This work introduces, for the first time, a model to select the proper polymer matrix type for natural fibers to enhance the sustainability of the automotive industry. The model was developed to rank different polymers and to determine their relative merits considering 20 different criteria simultaneously, including different physical, mechanical, chemical, environmental, and technical criteria. This work can support establishing a road map for proper selection of polymers in different engineering applications as well as increasing the reliability of the polymer selection process.

Conceptual Design of Kenaf Polymer Composites Automotive Spoiler Using TRIZ and Morphology Chart Methods

Spoilers are part of an automotive exterior bodywork system that acts to create additional down force for higher traction. In this paper, a new conceptual design of automotive spoiler component using kenaf polymer composites was developed using integrated TRIZ and morphology chart design method. The aim is to enable direct application of kenaf polymer composites to the spoiler design to achieve better environmental performance of the component while maintaining the required structural strength for safe and functional operation. The overall process involved two major stages, which are the idea generation and concept development. TRIZ method was applied in the idea generation stage where specific solution strategies for the design were created. In the concept development stage, the specific TRIZ solution strategies obtained were later refined into relevant alternative system elements using Morphology chart method. Finally, a new conceptual design of an automotive spoiler was developed using the combination of the identified system elements. The integrated TRIZ and morphology chart method were found to be new tools that can be used effectively in the concept design stage, especially in cases where direct material substitution is given the main focus for the new product development.

Validation of a Reduced Chemical Mechanism Coupled to CFD Model in a 2-Stroke HCCI Engine

Homogeneous Charge Compression Ignition (HCCI) combustion technology has demonstrated a profound potential to decrease both emissions and fuel consumption. In this way, the significance of the 2-stroke HCCI engine has been underestimated as it can provide more power stroke in comparison to a 4-stroke engine. Moreover, the mass of trapped residual gases is much larger in a 2-stroke engine, causing higher initial charge temperatures, which leads to easier auto-ignition. For controlling 2-stroke HCCI engines, it is vital to find optimized simulation approaches of HCCI combustion with a focus on ignition timing. In this study, a Computational Fluid Dynamic (CFD) model for a 2-stroke gasoline engine was developed coupled to a semi-detailed chemical mechanism of iso-octane to investigate the simulation capability of the considered chemical mechanism and the effects of different simulation parameters such as the turbulence model, grid density and time step size. The validation of numerical results was carried using an experimental study on the 2-stroke engine that was modified to operate in HCCI mode. Results confirm that the considered iso-octane chemical mechanism is able to predict the ignition timing of HCCI combustion in the 2-stroke gasoline engine but special care has to be taken to the numerical setting like grid size, time step size and turbulence model. Furthermore, the k-e RNG model is the best turbulence model for simulation of this case study coupled to the time step size of 0.25 crank angle degree and the average cell size of 1.35 mm.

Crash of automotive side member subjected to oblique loading

This paper presents the crash behavior analysis of automotive side member represented by aluminum square column subjected to oblique loading via finite element method. In crash research, energy absorption capacity is greatly affected by the deformation pattern, thus the collapse behavior and deformation pattern of this column is studied and observed. Effect of the geometrical parameters and loading angle, effect of these parameters on crashworthiness parameters that is specific energy absorption (SEA) and crush force efficiency (CFE) are explored. Observation on deformation pattern of the column shows that the bending is more apparent at the upper end for loading angle of 5 to 15 and at the bottom end for loading angle of 20 to 30. Results also show that SEA and CFE have less effected on the variation of column width. Ultimately, an equation that is expressed as a function of length and thickness is proposed to estimate crashworthiness parameters.

Rigidity Analysis of Kenaf Thermoplastic Composites Using Halpin-Tsai Equation

In this paper, the stiffness mechanical property of natural fiber reinforced thermoplastic composites is analyzed using composite micromechanical model. Kenaf natural fiber is selected as the reinforcement material in the composites construction while three types of commonly used automotive grade thermoplastic matrices, namely polypropylene, acrylonitrile butadiene styrene and polyamide 6 were selected to be reinforced with kenaf fibers. Their stiffness property was later analyzed using Halpin-Tsai micromechanical model at varying fiber content and fiber aspect ratio conditions. In all cases, theoretical results show that the kenaf reinforced thermoplastic composites stiffness increased linearly as the fiber contents were increased. Apart from that, results also show that the stiffness property also increases as the fiber aspect ratio was increased. Higher final composites stiffness property was also observed as stiffness matrix material is utilized in the composites formulation. The prediction results also provided valuable and quick insight as well as cost effective alternative to composite designers in assessing the stiffness performance of natural fiber composites especially those which are reinforced with thermoplastic matrices compared to conventional experimental technique for automotive product development purposes in addition to identifying the optimal parameter to be put into focus in their composites design to achieve the intended design performance specifications.

Performance of Aluminium Alloy Side Door Subjected to Pole Impact Test

This paper presents the performance of Aluminium Alloy side door subjected to side pole impact test. Aluminium Alloy is used in order to reduce the overall car weight. Therefore further improvements of the Aluminium Alloy side door system were carried out to obtain similar crash performance with the conventional steel side door system. The main crash performance properties are the internal energy, bending displacement, and mass. These properties were used to simulate the pole impact test using LS-DYNA Finite Element software. The improvements techniques used involved parameters such as thickness variation of the parts, ribs addition, beam shape variations, and combination of the factors. From the tests, three designs which include combination of parameters have met the target requirements. Thus, the use of Aluminium Alloy in side door system is acceptable provided there are improvements regarding the crash performance.

Crashworthiness Determination of Side Doors and B Pillar of a Vehicle Subjected to Pole Side Impact

Pole Side Impact Test is one out of three crash tests described by Euro NCAP standard for star rating of a vehicle and is required for assessing the Adult Occupant Protection. In this paper the goal is to determine the crashworthiness of side doors and B pillar in a Pole Side Impact Test based on Euro New Car Assessment Program (Euro-NCAP) using computer and simulation method. In this matter, a vehicle model has been prepared and meshed using Hypermesh and CATIA. The velocity of 29 km/h has been assigned to the vehicle which was on top of a cart while the pole has been assigned as a rigid static object based on Euro NCAP requirements specifically. Results show that different amounts of energy will be absorbed by each part, such as the side doors and the B pillar, and each part has a different effect on the crashworthiness of the vehicle in a Pole Side Impact Test. It can be concluded that to increase the amount of absorbed energy in a Pole Side Impact Test, the part which has more influence should be taken into greater consideration.

Investigation on Adult Occupant Protection in Car Pole Side Impact Using Various Material and Thickness of Side Doors and B Pillar

In this paper the objective is to study the effect of the material and thickness of the side doors and B pillar on crashworthiness and the energy absorbed in order to select a proper material and an optimized thickness to approach a five star car concept based on the Euro New Car Assessment Program (Euro-NCAP) testing Pole Side Impact. In this matter, four materials and five thicknesses have been chosen for the vehicle model and a total of twenty simulations have been conducted. The results showed that the best selected materials and thicknesses were high strength Steel 204M with a thickness of 1.2mm for side doors and 0.65mm for the B pillar, however, it is important to note that this selection is to maximize the absorbed energy not necessarily to reduce the total weight of the vehicle.