The screw press is a type of machine press used for extracting crude palm oil from the oil palm’s mesocarp, where its short driveshaft, a mechanical component for transmitting torque and rotation, is often found to be susceptible to failure. Since the initial damage to the short driveshafts in the shaft keyway area is associated with the frequent incidence of shaft failure, this research aimed to discover the root cause of this failure and how to prevent it using visual inspection and stress analysis methods as well as those of the fractography, metallography, chemical composition, and hardness tests. Using the descriptive method to analyse the collected data, the visual inspection and the fractography results of the research indicated that the fatigue crack failure of the short drive shaft in the palm oil screw press machine was caused by the fatigue crack initiation that was safe from stress concentration in its keyway areas. This crack initiation was followed by crack propagation as indicated in beach mark forms. Finally, the ductile fracture observed on the shaft surface was found to have resulted from the continuous rotational motion and the loading and unloading effect of the central shaft driving system.

This study aims to identify the effect of road surface to coil spring fatigue life using the strain-life approach. Strain signals were measured by attaching a strain gauge at the critical point of the component. The car was driven on a flat road, as well as uphill, and downhill paths. The results show that the downhill road provided the lowest fatigue life, of 1.5E+4 cycles to failure, which was 53 % lower than that of the uphill and 2,233 % lower than the flat road owing to the braking factor which resulted in a higher stress to the coil spring.

The purpose of this work was to predict the fatigue life of the AISI 1513 carbon steel due to the strains measured at a vehicle's lower arm. The strain signals were acquired using a strain gauge installed at the lower arm, and then the car was driven at various road surfaces. On the smooth road surface, the car was driven at a speed of > 70 km/h and on the rough road surface, at a speed of < 20 km/h. The results show that when the vehicle was driven on the rough road, the lower arm received higher stress, which provided a shorter fatigue life. The contour of the road surfaces provided a vertical load, directly working the lower arm and reducing the load vertically. The fatigue life for the rough road surface was 13,050 cycles to failure. This value was 91,195% lower than the fatigue life on the smooth road surface.

This paper presents a comparison work between the filtering methods of fatigue strain loadings using the frequency spectrum and the wavelet transform (WT), in which a raw loading signal can be simplified for purpose of simulation. For this reason, the Fast Fourier Transform (FFT) and the Morlet wavelet algorithms were used in order to transform the vibrational fatigue time series into the frequency domain signal, leading to the observation of the frequency characteristics of the signal. To retain high amplitude cycles in the FFT algorithm, a low pass filter technique was applied to remove the high frequency signals with small amplitude that are non-damaging. The departure of high frequency information smoothed the low amplitude cycles at high frequency events in the fatigue signal. The Butterworth filter was selected as the most efficient filter design as it retained most of the fatigue damage and also had the capability to remove 30 % of the original low amplitude cycles. On the other hand, the Morlet wavelet managed to remove 64 % of the original 59 second signal. This wavelet filtering method removed 34 % more than the similar procedure applied through the FFT approach. Hence, this fatigue data summarising algorithm can be used for studying the durability characteristics of automotive components.

This study aims to predict the fatigue life of the AISI 1513 carbon steel as the material for the vehicle lower arm subjected to road strains. Measurement of the strain signals was done by attaching a strain gauge at the left lower arm and driving the vehicle on clockwise and counter-clockwise roads at a speed of 30 km/h. According to the results based on the strain-life approach, the clockwise road gave the fatigue life of 2,600,000 cycles to failure, which was 1,862 % lower than the counter-clockwise road. It indicated that when the vehicle turned to the right, the lower arm on the left side subjected to a higher strain, resulting in a shorter fatigue life.