JOURNAL OF ENGINEERING AND COMPUTER SCIENCES

Performance Evaluation of Various Rock Classification Systems and Its Comparison with Existing Correlations for Rock Support

Muhammad Abu-Bakr Jamil — 2025-05-11

Rock mass classifications aim to provide a qualitative evaluation of the rock mass for the preliminary design of structures in rocks. The support system based on the rock mass classification has been applied to a variety of applications such as tunnels, powerhouses, and crude oil storage in Pakistan, and around the world. Bieniawski’s Rock Mass Rating (RMR), Barton’s Q System and Hoek and Brown Geological Strength Index (GSI) are the most widely known rock mass classification system and efforts have been made by various researchers around the world to develop correlations between them, the lesser-known systems Rock Condition Rating (RCR) and Rock Mass Number (QN) were also checked for its use in the construction industry since these systems omit some parameters used during field investigation. This research is an attempt to develop a correlation between RMR, GSI, and Q System of Rock mass classifications on a statistical approach using 240 data points recorded through a geological logs of exploratory drifts and tunnel logs during excavation for the Gulpur Hydropower Project, Pakistan. The correlations presented in this research were developed using various statistical approaches (i.e., linear, logarithmic, power, exponential, and polynomial) to develop correlation which not only allows us to compare the results of various statistical approaches but also tells us which approach gives the best results for correlation between two rock mass classification systems.

PREDICTION OF RESIDUAL STRESSES OF 3D-PRINTED PLATES UTILIZING SYSWELD

ABDELRAHEIM AHMED — 2025-05-15

This work studies the evolved residual stress after finishing each manufacturing phase. The SYSWELD finite element software was utilized for predicting the residual stress after clamping, unclamping, surface finishing and heat treatment. The study was based on the required number of layers. Fourteen set of results for different number of layers production between 5-layers and 150 layers.

The study ends with providing readymade information about the expected residual stress after each process of additive manufacturing.

Prediction of Residual Stresses of 3d-Printed Plates Utilizing SYSWELD

Abdulrahman A. Alrumayh — 2025-05-11

Investigating how residual stress distribution evolves with increasing build height (number of layers) is crucial for understanding scalability and dimensional control in additive manufacturing. Post-processing, such as unclamping, machining, and heat treatment, interacts with the existing stress state and influences varying build heights (number of layers). This was the subject of speculation of many up-to-date researchers. Among the drawbacks of the residual stress is its impact on fatigue crack propagation. This work investigates the residual stress prediction in 3D-printed plates using the SYSWELD simulation software. The investigation covers the evolved residual stress after finishing each of the manufacturing phase. It focuses on the Wire Arc Additive Manufacturing (WAAM) process, a widely used metal 3D-printing technique. The SYSWELD finite element software was utilized for predicting the residual stress after clamping, unclamping, surface finishing and heat treatment. The study aims to improve simulation accuracy by incorporating a round-layer design model, which better represents the actual deposition process compared to traditional layer-based approaches. Fourteen sets of results for different numbers of layers, ranging from 5 layers to 150 layers. The use of SYSWELD facilitate modeling the thermal and mechanical behavior of the printed plates, incorporating factors such as heat input, material properties, and cooling effects. The study ends with providing a way of predicting the expected residual stress after each process of additive manufacturing.

Left-Turn Geometrical Attributes: A Microsimulation Approach to Signal Optimization

Mohammed S. Alfawzan — 2025-05-11

The ordinary signalized intersection geometry and control are facing tremendous traffic challenges. Signal timing control and innovative geometric designs contribute to mitigate congestion at signalized intersections worldwide. The author has investigated a geometric design case in Qassim region, in Saudi Arabia which involves a roundabout intersection. The intersection was recently reconstructed with a new geometric design involving partial Exclusive Left- Turn Bays. The research was aimed to investigate three different geometric designs of a partial exclusive left turns signalized intersection, a roundabout intersection, and a proposed full exclusive left turns signalized intersection. Analyses for the existing case, the roundabout, and the exclusive left turns were coded and validated using microsimulation model (VISSIM) with field collected data from the studied signalized intersection. The results showed that, despite fewer improvements in vehicle delays and queue length (meters) of the proposed full exclusive left turns in the comparison with the existing partial exclusive left turns, the geometry designed with a roundabout case yield shorter queue lengths and vehicle delays than the case of signalized intersections designed with partial or full exclusive left turn bays in certain traffic volume levels.

Effect of the Aspect Ratio on the Buckling Load of Unidirectional Carbon Fiber Reinforced Composites

Mansour Alturki — 2025-05-11

Elastic instabilities, such as buckling and snapping-through, serve as key mechanisms in metamaterials and periodic structures designed for self-centering, energy absorption, and dissipation. These systems rely on single or multiple buckling events of interconnected axially compressed elements. A promising candidate material for such elements is the unidirectional carbon fiber-reinforced composites, provided that elastic buckling precedes inelastic damage failure. This study presents a numerical investigation to examine the failure stress of unidirectional carbon fiber-reinforced composites with various aspect ratios (AR). Finite element analyses were performed on tested specimens of unidirectional carbon fiber-reinforced polymer composites found in the literature. Results indicate that a minimum AR of 28 is required to induce buckling failure rather than other modes, with Euler’s equation sufficiently predicting critical buckling stress in this range. On the other hand, for AR values between 15 and 28, compression-shear or shear failure becomes dominant, while AR below 15 typically results in compression failure. Accounting for shear correction and material nonlinearity enables precise prediction of critical buckling stress across all AR.