The leaf spring is one of the main components in an automobile which carries the weight of the vehicle and passenger as well as absorbs the vibration and shock produced due to road irregularities. The weight, natural frequency, stress developed, energy absorption, fatigue life, etc. are the key factors that need to be considered to design a leaf spring. Towards that, a novel design integrating a Negative Stiffness Honeycomb Structure (NSHS) in the leaf spring is proposed. The proposed design and the traditional leaf spring are analyzed using the commercially available Finite Element Method (FEM) software Abaqus. Both the traditional and NSHS models were created using Solidworks and modal, harmonic, structural, and transient analyses were performed. It is found that the natural frequency of the NSHS leaf spring is well above the frequency produced due to road irregularities although it is lower than the traditional spring. The total weight of the NSHS spring structure is reduced significantly by 30.73% compared to the traditional spring. Structural analysis shows a lower stress development and higher energy absorption capacity for the NSHS leaf spring. Transient analysis reveals lower mean stress in the proposed NSHS spring. The fatigue life is also found to be 82.78 % higher in the proposed design. The NSHS-incorporated novel leaf spring design may be an excellent alternative to the traditional leaf spring.

This work focusses on the crack growth behaviour of the compact tension specimen under mixed-mode loading, and numerical investigation using ANSYS Mechanical APDL 19.2 extended finite element software with different loading angles. The fatigue life is predicted under constant amplitude fatigue loading using the Paris’ law. The predicted values of the fatigue life in the present study provide consistency with the experimental and numerical results. In addition, the study showed that the direction of crack growth follows the same literature trend of experimental results. According to the results of the crack growth path, there is no effect of changing the geometries thicknesses on the crack growth trajectory. Its only effect is the resistance to higher plastic deformation which decreases as the thickness increases.

This work investigated and predicted the fatigue life durability of Austenitic Stainless Steel 316L due to its importance in plant industries worldwide. Modelling and simulations were performed to clarify the fracture as well as stress distribution using integrated mechanism. Experimental fatigue validations were also carried out to demonstrate the effect of various fatigue life parameters. Various loading conditions with variable load amplitudes were validated utilizing a frequency of 5 Hz and a stress ratio of 0.1. The accuracy of the simulation results were also verified based on the experimental data. High consistencies between the predicted fatigue life and the experimental results were achieved which increases the validity of the built model.

There are literally several studies accomplished to predict the fatigue life of leaf springs but estimation of fatigue life of a parabolic leaf spring by using CAE tools has not yet been executed in the past. Parabolic spring is an important component in a vehicle suspension system. It needs to have excellent fatigue life and in today’s scenario manufacturers rely on constant loading fatigue analysis. The objective of this work is to perform the fatigue analysis of parabolic leaf spring by three different methods where CAE analysis is performed to observe the distribution of stress fatigue life and damage using Goodman approach. In this work, fatigue life of the parabolic leaf spring is determined as per SAE spring design manual and experimentally by testing on full scale fatigue testing machine. ANSYS is used for CAE solution for the prediction of leaf springs fatigue life considering stress theory. The fatigue life estimated by all three modes is then compared for the purpose of validation. The methodology used in this paper brings a practical approach to the professionals in the industries who are engaged for design of mechanical components.

The main objective of this paper is to study the effects of haversinse and triangular loading waveforms on the fatigue life of Hot Mix Asphalt (HMA) specimens. Effects of load duration, rest period and stress level are also studied for the asphalt mixtures at 25oC. An indirect tensile test with strain control was performed to determine the fatigue life of asphalt. The fatigue tests were performed at two stress levels (170 and 250 kPa), two waveforms (haversine and triangle), three load duration (100, 200, 400 ms), and two rest period to load duration ratios (4 and 9). The obtained results showed that fatigue life of haversine waveform is less than fatigue life of triangle waveform. As the area under the loading curve is increased (stress level is increased or deformed), effect of rest period on the fatigue life decreases. On the other hand, as the tire contact area is increased, the induced tire pressure reduction decreases its destructive effects on the asphalt layer. As the load duration is decreased, fatigue life will increase. This effect is more pronounced for lower stress levels than the higher stress levels.

A land-based gas turbine may operate at the different environment including corrosive and dusty environments. These conditions can cause early damages in the “cold” parts as well as in the “hot” parts of the gas turbine. In this research, fatigue life of a compressor blade is predicted with and without damages. Damage is considered as a notch at the blade and is classified as three types of short, medium and long notches. These are numerically simulated in the compressor blade and fatigue crack initiation life is calculated. Stress analysis is carried out using finite element analysis followed by fatigue life calculations. Furthermore, the influence of blade tip displacement on life of the undamaged and damaged blade is investigated. Moreover, the effect of damage & apos; s size and location on blade’s life is reported. This procedure can be tuned with corrosion damages observed during the minor inspection where the gas turbines are operating in the unusual environments.