Applied Mechanics and Materials Vols. 773-774

Abstract: This paper investigates the effect of bolt gauge on the face bending behaviour of concrete-filled Square Hollow Sections (SHS) in Hollo-Bolted connections. A set of full-scale experiments were undertaken to examine the effects of varying the bolt gauge on the SHS face bending behaviour while controlling all other parameters. Typical experiment involved one row of two bolts pulled out of concrete-filled SHS. A special dummy bolts were manufactured to the exact size and geometry of open Hollo-Bolts, and were used in the experiments to remove the influence of any deformation associated with the real Hollo-Bolts, and isolate the face bending behaviour. Non-contact video-based equipment was used to record the SHS face deformation. This deformation is recorded as force-displacement relationship which is commonly used to represent the structural behaviour of similar components, and typically defined by initial stiffness, yield force and post yield stiffness. Across the range considered in this investigation, it was found that varying the bolt gauge to SHS width ratio have a significant effect on the concrete-filled SHS face in bending component. Both the initial stiffness and the yield force of the component were found to increase with the increase of the bolt gauge. The Post-Yield stiffness was not affected by the change in bolt gauge.

Abstract: This study aims to investigate the crashworthiness behavior of hollow Al-based functionally graded material (FGM) box. In order to introduce the concept of FGM, several holes are known as trigger points were drilled on a thin-walled Al column. The column was divided into four segments and each segment has a different number of trigger points. The difference number of trigger points on each segment produces the different structural strength. Quasi-static loading test was conducted in order to observe the deformation pattern occurred. The corresponding graph of force versus distance then was analyzed to obtain the value of energy absorption for each sample. Five samples of different segment arrangement were tested, namely, S1a, S1b, S2, S3 and S4. From the results obtained, the sample S1b give the best results with the highest value of energy absorption. This sample is designed with a large number of trigger points in the first segment, followed by a reduced number of trigger points until the end of the segment. The quality of crash box can be improved by introducing FGM concept. This type of crash box is able to produce a grade of absorption crushing energy. Thus it can reduce severity of injury during an accident.

Abstract: Recently Metal injection molding is selected as a vital process in producing large amount of small part with complex geometry and intricate shape. This process is lead to solve cost effective issue in manufacturing fields. Feedstock composition behavior categorized as one of impact factor in determines the victories in metal injection molding process. Thus this paper is focused on optimizing the strength of green part by applied Taguchi Method L9 (3⁴) as optimization tools during injection process. The composition of feedstock is 55% powder loading (PL) were injected by injection molding machine .Several injection parameter were optimized such as injection temperature (A), barrel temperature (B), injection pressure (C) and Speed (D) The results analyzed by using Signal to Noise Ratio (S/N ratio) terms. The highest green strength is A₂, B₂, C₂, and D₂

Abstract: Sliding contact will experience wear in majority of mechanical components during their service life where it reduces the performance of the components. The capability to predict the evolution of reciprocating wear scars, such as the scar’s width and depth, would be a valuable tool when designing mechanical components. Wear scar mechanism behaviour is characterised during stabilized cycle reciprocating sliding wear test of Ti-6Al-4V investigated using pin-on-flat arrangement under variable duration of sliding. The test samples were analyzed using profilometer test, optical microscopy test, Scanning Electron Microscopy (SEM) test, Energy Depressive X-ray (EDX) test and Vickers Hardness (HV) test. Stabilised high number of cycles shows low wear rate and initiation period of low cycles produced higher wear rate.

Abstract: The use of biopetrol fuel as alternative fuels in gasoline engine has been around for many years and Ethanol-petrol has the potential to be used as alternative fuel that can reduce the total CO₂ emission from internal petrol engine. However, the changes of bio-petrol is a very complex and need further understanding for researchers due to the relevance of the increase in the petroleum price and the future environmental regulation. This review paper focuses to ascertain a new approach in potential on ethanol-petrol blends operating with a petrol engine especially the effects of ethanol gas petrol blending ratio and variant types of ethanol on performance and emissions of petrol engine. It is shown that the variant in biopetrol blending ratio and engine operational condition are reduced engine-out emissions and increased efficiency. This paper presents on a review on three different types of ethanol like sugar cane, wheat and corn with various blended rates. Investigation framework study on how to complete the research is also included in this paper.Keywords: biopetrol, petrol engine, performance, emissions, biopetrol fuel properties

Abstract: This paper presents numerical analysis of stress intensity factors (SIFs) of inclined cracks due to mechanical mismatches. According to literature survey, tremendous amounts of SIFs can be found elsewhere. However, the SIFs for inclined cracks are difficult to obtain especially when mechanical mismatch at the crack interface are considered. ANSYS finite element program is used to model the cracks embedded in plain strain plates. The cracks are oriented at the interface between two different materials and subjected to mode I tension loading. It is showed that when mechanical mismatches are introduced the mode I SIFs reduced and on the other hand mode II SIFs increased. When the cracks are inclined, the mode I SIFs diverged but it is not for mode II SIFs and gradually increased when compared with the normal cracks.

Abstract: This paper presents the combination technique in developing the woven kenaf fiber that is used as a new method to improve energy absorption performance. This method focuses on the effect energy absorption of angle orientation. Due to the low density, natural fiber such as kenaf fiber provides comparatively good mechanical properties. Thus, natural fibers have high potential for better reinforcement in light weight structures on automotive applications. Total force, total energy, and energy absorption of natural fibre reinforced composite for different type’s natural fibre and angle orientation are discussed and reviewed.

Abstract: Vibration analysis has proven to be the most effective method for machine condition monitoring to date. Various effective signal analysis methods to analyze and extract fault signature that embedded in the raw vibration signals have been introduced in the past few decades such as fast Fourier transform (FFT), short time Fourier transform (STFT), wavelets analysis, empirical mode decomposition (EMD), Hilbert-Huang transform (HHT), etc. however, these is still a need for human to interpret vibration signature of faults and it is regarded as one of the major challenge in vibration condition monitoring. Thus, most recent researches in vibration condition monitoring revolved around using Artificial Intelligence (AI) techniques to automate machinery faults detection and diagnosis. The most recent literatures in this area show that researches are mainly focus on using machine learning techniques for data fusion, features fusion, and also decisions fusion in order to achieve a higher accuracy of decision making in vibration condition monitoring. This paper provides a review on the most recent development in vibration signal analysis methods as well as the AI techniques used for automated decision making in vibration condition monitoring in the past two years.

Abstract: This paper studies the detection of twisted blade in a multi stages rotor system. Experimental study was undertaken to simulate twisted blade conditions in a three stages rotor system. The feasibility of vibration analysis as the technique to detect twisted blade based on the rotor operating frequency and its blade passing frequency was investigated in this study. Experimental results show that twisted blade can be easily detected by looking into the pattern of the vibration spectrum and its individual peaks.

Abstract: In order to reduce cost of production and decrease environmental pollution, so many research work has been conducted and still ongoing as to the possibility to use kenaf fiber in high technologies production. Its shows that kenaf fiber have potential reinforced fiber in thermosets and thermoplastics composites. This paper presents the various of challenges to produce kenaf as a reinforcement which mean to identify the limit of kenaf fiber performance after over all of challenging factor. The main factor that touch on interphase, water absorption, chemical treatment and fiber fraction which mean affect the performance of kenaf fiber as a reinforcement are discussed.