Applied Mechanics and Materials

Preface

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935

Simulation and Uncertainty Analysis of Buckling Behaviour of Thin Cylindrical Shell under Compression

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Azizul Hakim Samsudin, Farhah Nadhirah Md Nordin, Mohd Shahrom Ismail, Ho Quang Nguyen
This study analysed the buckling behaviour of thin-cylindrical shells under axial compression, addressing the persistent disparity between theoretical predictions and numerical simulations. The research investigated the influence of key parameters height, Young's modulus, and thickness on the critical buckling load. A Finite Element Analysis (FEA), specifically a Geometrically and Materially Non-Linear Analysis (GMNA), was performed using the software ABAQUS to model the shells. To bridge the gap between simulation and theory, a mathematical model for uncertainty analysis was developed in MATLAB, employing the Monte-Carlo Simulation (MCS) and referencing Rankine's theory. This study introduces a novel analytical framework that integrates Finite Element Analysis (FEA) and uncertainty analysis to resolve discrepancies in buckling predictions for thin cylindrical shells. The model's accuracy was validated with a maximum error of less than 13% compared to existing studies, and the uncertainty analysis demonstrated a robust standard deviation of 0.249 (less than 1%). The findings revealed that thickness is the most influential parameter; a 10% increase in thickness led to a 10.86% increase in the buckling load. Young's modulus had a moderate impact, with a 10% increase causing a 0.28% rise in the buckling load, while height was the least influential, with a 10% increase leading to only a 0.1% increase. This research provides valuable insights into the complexities of predicting critical buckling loads, highlighting the distinct impact of geometric and material properties on the structural behaviour of cylindrical shells.

Hydrogen Fuel Cell Commercial Vehicles: A Comparative Review of Sustainable Freight Transport

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Gunasilan Manar, Mohd Supian Abu Bakar, Risby Mohd Sohaimi, Muhammad Imran Najeeb, Mohammad Asyraf Mohammad Rizal, Hamdan Ya
The freight transport sector, which primarily relies on heavy-duty diesel vehicles, accounts for approximately 25–30% of worldwide transport-related greenhouse gas (GHG) emissions, underscoring the critical need for decarbonisation. Hydrogen fuel cell commercial vehicles (HFCVs), otherwise, are emerging as a viable alternative for long-haul freight, strengthened by advancements in fuel cell technology and supportive national energy policies. Meanwhile, the battery electric vehicles (BEVs) excel in short- to medium-duty applications due to their high efficiency, but encounter challenges related to charging delays, infrastructure requirements, and reliance on the electrical grid. However, the HFCVs provide rapid refuelling and extensive ranges; yet they face obstacles due to elevated hydrogen prices, insufficient refuelling infrastructure, and fragmented policies. This review offers a comparative evaluation of hydrogen fuel cell vehicles, battery electric vehicles, and diesel vehicles in terms of technical, environmental, and economic factors, encompassing range, efficiency, lifecycle emissions, and infrastructure expenses. Moreover, this review outcome has indicated that China surpasses others in adoption due to robust national strategies at the same time, Europe gains from the Green Deal and Fit-for-55, and North America progresses through industry-led initiatives but faces challenges from fragmented regulations, with readiness indices of 3.8, 3.7, and 3.3, respectively. Realising scale necessitates synchronised policy, infrastructural investment, and intersectoral collaboration. This review study also provides empirical insights to inform sustainable freight transition strategies and emphasises HFCVs as a feasible alternative for decarbonising long-haul transportation.

Heat Loss Parametric Study on Laminar Flow in a 3-Dimensional Rectangular Heating Duct in Cold Weather

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Abdullatif A. Gari
Heat losses from heating air ducts underground are used in many applications such as heating and air conditioning in cold weather. Researchers worked on heat losses to understand different ways to reduce heat losses to the environment. This project studies a 3-dimensional model of heating rectangular duct in cold surroundings. The model was done numerically. The numerical grid was tested to reach a reasonable approximation and a comparison with correlations from literature showed good agreement. Moreover, parametric study was carried out to study the effect of different parameters on heat losses. These parameters were Inlet velocity Vo, Inlet temperature To, outer heat transfer coefficient ho, and surrounding temperature T∞. Results showed that higher inlet velocity, inlet temperature, and outer heat transfer coefficient increases the total heat loss to the surroundings while higher surrounding temperature decreases the total heat loss to the surroundings.

Noise Reduction of Jet by Passive Control

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Felix Mwiya, Lencho Dereje Futaza, Wisdom Simwila Kalunga, Abinash Rout, Dharmahinder Singh Chand, Yared Alemayehu, Prakash Jadhav
This research focused on noise reduction in jets using chevron passive control method, the nozzle designs with varying chevron types were subjected to CFD analysis and experimental analysis to understand pressure distribution patterns in the far field. This research distinctively analysed chevron performance through pressure distribution in the far field and not based on nozzle acoustic power dis-tribution, a surface phenomenon. Four models of nozzles namely base, chevron, wave and tabular were designed, manufactured and extensive analysis in both computational and experimental approaches was carried out. The sound pressure level (SPL) was calculated along with its percentage reduction for three models by taking the base model as reference model. The scientific results showed that among all models, wave is the least noisy with reduction of 3.3% and 1.16% SPL in computation and experiment respectively. On the other hand, the base model found to be the highest noisy model both computationally and experimentally.

Design and Trails on Ionic Plasma Thruster for Aerospace Applications

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Yaswanth P. Sai, Kumar Sah Supen
Ionic plasma thruster is advanced propulsion technology utilized for space applications. Scientific research remains focused on the development of efficient and effective thruster technologies for space exploration. The technology of ionic plasma thruster is notable for its ability to achieve high specific impulse and fuel efficiency. This study outlines our study on plasma and endeavours to enhance Ionic Plasma Thruster through the utilization of innovative methodologies and materials. The experimental setup utilizes electrodes energized by a 1000 kV power module and Lithium-Ion batteries. The design of electrodes is to enhance the concentration of flow electrons for a significant ionization, after ionization the discharged particles (ions) causes the thruster to the system. In addition to ameliorate the thruster, neodymium magnets are strategically positioned, and to expedite the movement of ions and improve the ionization processes. This paper arrays our study and development on plasma ionization and ionic plasma thruster thorough examination of our experimental configuration, methods, and initial findings. Our ongoing research and development efforts aim to expand the technology of ionic plasma thruster, with the goal of enabling more efficient, cost effective and sustainable space exploration missions.

Finite Element-Based Structural Integrity Assessment of a Payload Chassis: A Material Trade-Off Study for PSLV Launch Conditions

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Niketan Pawar, Nikhil Navle, Aditee Joshi, Damayanti Gharpure, Subra Ananthakrishnan
This paper presents a comprehensive structural, modal, and random vibration analysis of the SEAMS Payload using ANSYS 18.1 simulation tools. As a preliminary design-phase study, its goal is to perform a trade-off analysis between common aerospace materials before physical prototyping and validation. The study evaluates three aluminum alloys—5052- H32, 6061-T6, and 7075-T6—to optimize the payload frame structure for mechanical stresses encountered during launch and space operations. The analysis includes static structural loading to assess deformation and stress distribution, vibrational modal analysis to determine natural frequencies and mode shapes, and random vibration analysis to simulate launch-induced dynamic excitation. The simulation outcomes highlight the critical role of material selection in enhancing structural integrity, maximizing safety margins, and ensuring mechanical reliability of the payload in harsh launch environments.

A Systematic Review on Bioinspired Robotic Grippers and Manipulators

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Aiman Zakir, Hafsa Masood, Bhumika Yadav, Shruti Sharma, Aditi Surya Kamal, Pooja Bhati
Across land, sea and air, nature has inspired researchers in countless ways, showcasing unique approaches to enhance grasping and manipulation techniques within robotics. The Flora and Fauna have served as ideas for enhanced flexibility, bending, maneuverability and adaptability for various grippers and manipulators in recent times. This study intends to explore the various fabrication methods, material choices and actuation processes used for these bioinspired robotic structures, as well as highlight the different applications, advantages and challenges. As traditional robots lacked the ability to work in unstructured environments and handle delicate operations, this triggered the need for bioinspired design. Through this paper, we connect the principles from nature to engineering, identifying the gap to achieve more efficient, versatile and durable robotic manipulators.

Development and Simulation of an Algorithm for UAV Swarm Coordination and Collision Avoidance

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Samuel David Iyaghigba, Oluwatumise Shadrack Asere, Abdussalam El-Suleiman, Akanimo Jimmy Ukim, Sadiq Thomas
The use of Unmanned Aerial Vehicles (UAVs) is increasing as their usage enhance many activities in our modern world. These include their specific roles in warfare, surveillance, agricultural activities, entertainments with attendant economic importance. In areas grappling with insecurity challenges due to banditry, kidnappings, oil spillage and theft, farmers and herdsmen clashes, utilizing more than one UAV in an area for surveillance is not only good but more advantageous. If many UAVs are used in an area at the same time, they are termed swarm or group of UAVs. Their operations in this manner, are seen as more scalable and reliable mode of using UAVs in current and future applications. Thus, usage of multiple UAVs that operate together as a cohesive unit are redundant and scalable, performing tasks that would be challenging or inefficient for a single UAV to accomplish. However, operating a group of UAVs as one unit can become expensive and risky if they are not properly coordinated. The UAVs may collide, causing catastrophic damage and requiring costly repairs. The need for autonomous coordination therefore comes from the vast number of vehicles, which might be intrinsic members of the system as a whole. Also, all UAVs in the swarm are to contribute to the effective execution of task without wasting resources. These imply that an intelligent coordination algorithm that implements awareness for swarm UAVs to avoid risky states is required. This paper presents the development and implementation of an algorithm for intra-swarm collision avoidance by treating each UAV in a swarm unit as individual agent capable of a homogenous number of tasks modelled as contours using their field of view and received signal strength indication.

Toward a ML Framework for Multisensory Human Health and Awareness

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Francis Anyebe Oteikwu, Osezua Ejodame, Norman Osa-Uwagbue
This paper proposes a conceptual framework for an intelligent soldier monitoring system, integrating multimodal sensor networks with Multimodal Large Language Models (MLLMs) to advance battlefield healthcare and situational awareness. The envisioned architecture combines physiological sensors (e.g., heart rate variability, cortisol levels, core temperature) with environmental sensors (e.g., acoustic, visual, thermal) through an edge-AI processing pipeline. Based on our literature review, we target three key limitations in existing systems: (1) real-time data fusion latency (aiming for <100 ms), (2) predictive health analytics accuracy (aiming for >90% for critical conditions), and (3) adaptive threat response capabilities. Our research suggests that the proposed technologies are at an early conceptual stage, supported by analysis of existing component technologies not yet integrated into a cohesive system. We identify challenges in power efficiency (targeting <50 mW per sensor) and ethical implementation, proposing solutions such as on-device processing and explainable AI. This work establishes a theoretical foundation and a research roadmap for future development of advanced military monitoring systems, balancing performance with operational and ethical considerations..

Fit-Track: Edge-Intelligent Device-Free and Battery-Free Fitness Tracking

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Samuel Dayo Adesola, Abdurrahman Said, Usman Saleh Toro
Nowadays, many people have difficulty accessing dedicated exercise facilities in the gymnasium. This could be due to hectic work schedules or constant travel. In such a scenario, a person will struggle to stick to an exercise routine to keep fit. Though people have adopted electronic devices for fitness tracking, such devices usually rely on batteries and must be worn in most cases to monitor fitness activities. Hence, we proposed the design of Fit-Track, a battery-free and wearable device-free fitness tracking system with edge intelligence. Fit-Track proposes using piezoresistive (PZR) sensors to track specific exercises (such as steps, pushups, and squats). The PZR sensors are interfaced with Arduino nano33 BLE sense for data processing and wireless transmission to a mobile phone. During the design of Fit-Track, we faced challenges of power supply, interference, and computation. Those challenges were addressed through adopting a multi-modal (solar and kinetic energy harvesting) power supply, attaching a PZR sensor to each foot, and developing algorithms (both intelligent and signal processing) based on the nature of the exercise carried out for tracking counts of the activity. Experiments on Fit-Track for the various exercises (steps, push-ups, and squats) with edge intelligence showed a minimum accuracy of 99 %.

Piezoelectric Foot Mat Energy Harvesting for Low-Power Applications: Exploring the Impact of Weight Distribution and Step Frequency

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Ibrahim Abdulwahab, Aminu Jibrin Aliyu, Peace Efemena Peter, Yusuf Sani Abu, David Enemali Abah, Nuraddeen Adam Iliyasu
In recent times, electricity has become a great necessity for everyone and almost everything around the globe. The ever-growing population and increase in electronic devices have increased the rate of energy consumption. In a bid to meet this demand, all forms of energy are utilized and still undergoing research. This work aims at generating and harvesting electrical energy by converting mechanical energy from pressure exerted (footsteps) on the material into electricity by a phenomenon called piezoelectricity. A group of 40 piezoelectric crystals were constructed and connected via a parallel connection of 5 by 8. The piezoelectric crystals showed different results to varying weights and oscillations at a fixed time. These results were visible on the plot of voltage generated versus weight and on the plot of voltage generated to number of steps. These graphs showed that the greater the weight the more voltage and also more voltage is generated with increase in number of footsteps.

Adaptive Neural Network-Based Feedforward-Feedback Controller for Nonlinear Dynamic System

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Kayode Williams Olalere, Bunu Thalib Abubakar, Bernice Gunde Izuwunum, Isaac Ijeoma, Elijah Reuben Kwetishe, Oluwanifemi Adediran, Opeyemi Ayokunle Osanaiye, Temitayo Samson Ogedengbe
This study investigates the deployment of adaptive neural network-based control strategies for nonlinear dynamic systems, emphasizing the integration of Echo State Networks (ESNs) into a feedforward-feedback control architecture. Traditional controllers relying on precise mathematical modeling often fail to cope with the complexity of systems exhibiting high nonlinearity, time-varying parameters, and external disturbances. The proposed ESN-based approach harnesses reservoir computing to construct a lightweight, data-driven model capable of accurately capturing system dynamics in real time. The feedforward module provides anticipatory control actions, while the feedback loop compensates for deviations, enabling rapid convergence and robustness against parametric drift. Comparative analysis with conventional PID and LQR controllers reveals superior performance in terms of tracking accuracy, stability, and noise resilience. Preliminary simulations predict reduced steady-state error and improved dynamic response even under uncertain operating conditions. This architecture presents a scalable and efficient alternative for advanced applications in robotics, aerospace, and industrial process control. The findings affirm the viability of ESNs in redefining adaptive control paradigms by combining interpretability, computational efficiency, and real-world adaptability. Reference to this paper should be made as follows:MCE 2025, MCE825. (2025) ‘Adaptive neural network-based feedforward-feedback controller for nonlinear dynamic systems.

Top-Level Structural and Mechatronic Design of a 6WD Outdoor Autonomous Delivery Robot with a Redesigned Adaptive Climbing Rocker-Bogie Suspension

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Chidalu Ndupu Sixtus, Fauzeeyah Usman Abdullahi, Demilade Magaji, Nyangwarimam Obadiah Ali, Thomas Sadiq
This paper presents the design, construction and development of an autonomous delivery robot aimed at structured environment such as university campuses, hospitals, residential estates and factories. The system integrates a six wheeled differential drive platform with a redesign adaptive climbing rocker-boogie suspension system. It makes use of an array of high precision sensors such as LIDAR, ultrasonic sensors, IR sensors, depth camera, real time kinematics (RTK) GPS for real time navigation and obstacle detection. The autonomous delivery robot is managed using ROS 2-based system running on an Nvidia Jetson nanoand features a mobile application for remote tracking, management and control. Simulation based testing in gazebo as well as experimental validation was conducted to evaluate the robot’s autonomous behavior and delivery performance.

Reduction of Path Length of Notable Path Algorithms Using the KNS Algorithm

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Kenneth Christopher Ugwoke, Nnanna Nwojo Agwu, Saleh El-Yakubu Abdullahi
Path planning refers to designing a reliable, feasible, optimum, safe, and collision-free path with the shortest distance that takes a mobile robot from the start position to the goal point within an environment. To ensure the successful operation of a robot, an effective and efficient Path planning technique that guarantees obstacle avoidance and an optimal path must be adopted. This paper applies a novel path length reduction technique – the Kenneth, Nnanna, and Saleh (KNS) algorithm-to notable path planning algorithms (APF, A*, RRT, and RRT*) to shorten their path length by reducing the waypoints' bends and retaining the obstacle avoidance capability of the algorithms. We simulated applying the technique to different notable algorithms in an environment configured with varying obstacles. We compared the resultant paths with the original paths. The results show that the KNS algorithm is very effective and can significantly reduce the path length of the notable algorithms.

Enhancing Energy Harvesting from Low-Frequency Vibrations via Topology Optimization of Bimorph PVDF Cantilevers

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Patricia M. Aguilar, Louise D. Rayos Del Sol, Candy C. Mercado
Mechanical vibrations are abundant in human-made environments and can be harnessed using piezoelectric transduction. Among the piezo materials, piezoelectric polymers exhibit flexibility and mechanical compliance, improving resilience to shock and deformation—suited for low-frequency high strain environments. In this paper, distinct designs of piezoelectric active area were topology optimized using ANSYS. Three designs of bimorph cantilevered energy harvesters were developed to obtain the optimum material layouts of piezoelectric PVDF, maximize the voltage output, decrease the resonant frequency, and reduce the amount of material needed. Two additional designs with varying volume retainment were also simulated to investigate the effects of optimization parameters. The best topology optimized design, #2, had a resonant frequency of 16.9 Hz and a piezo voltage of 1.08E-3 V/mm3 normalized to the amount of remaining PVDF after optimization. Although the frequency is still higher than the target ambient energy sources, this study showed that topology optimization in conjunction with design can be used to define structures leading to the energy harvesting application frequency.

Comparative Study of YOLOv5, YOLOv8, and YOLOv11 for Dust Detection in Voice Coil Motor Assembly

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Kreetiwat Chaiyasin, Veena Phunpeng, Sorada Khaengkarn, Kitsana Khodcharad, Tanporn Hengmeechai
Detecting microscopic defects in precision manufacturing remains a major challenge, particularly in hard disk drive (HDD) production where sub-millimeter dust particles on the Voice Coil Motor Assembly (VCMA) can cause performance degradation or early device failure. This study presents a comparative evaluation of three YOLO object-detection architectures—YOLOv5, YOLOv8, and YOLOv11—applied to high-resolution dust detection on VCMA components. All models were trained and tested using the same annotated 5-megapixel dataset under identical experimental settings to ensure fair comparison. The results show that YOLOv5 achieved the highest precision (0.640) and the highest mAP50–95 (0.253), indicating stable localization performance across strict IoU thresholds. YOLOv8 produced the highest mAP50 (0.500), reflecting strong localization accuracy at IoU 0.5, while maintaining moderate precision (0.633) and lower recall (0.455). YOLOv11 obtained the highest recall (0.636), successfully capturing the largest proportion of true dust particles, though with lower precision (0.335) and weaker mAP values, revealing a higher rate of false detections. Overall, the findings highlight clear trade-offs among the models: YOLOv5 offers the most balanced performance, YOLOv8 excels in spatial localization, and YOLOv11 is suitable for scenarios where maximum defect coverage is prioritized. These insights support the selection of appropriate detection architectures for automated micro-defect inspection and contribute to the development of AI-driven quality-control systems in HDD manufacturing.

Development of Workpiece Positioning System for Machining Micro-Pits of Hip Implant

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Azli Yahya, Nasrul Humaimi, Kartiko Nugroho, Zahran Khudzari, Jaysuman Puspanathan
This paper describes a development of Electrical Discharge Machining (EDM) system for biomedical application. In general, the mechanism of EDM comprises of mechanical structure and electronic control system. This laboratory scale of the EDM system has a capability to accommodate the machining of hip implant which employs low power generator. The holder for the workpiece is created to accurately position the hip implant, ensuring that the machining angle of the implant directs the micro-pits precisely toward the workpiece. A traditional linear x-y-z axis setup (Cartesian coordinate system) is utilized, along with two types of spherical coordinates (swing-swing and swing-rotate configurations). By the results of performance test, the Swing Motor behaves differently to the common servo motor. The Swing Motor is affected by unbalanced load and gravity in which the Ziegler-Nichols PID optimization method has been altered from the conventional model. The average of absolute error is 0.2308 degrees. However, optimized PI controller by Ziegler-Nichols method is able to eliminate the effect in term of final achieved position (steady state condition) and fulfil the objectives.

Elimination of Bond Pad Crack through Application of Initial Force via Force Profiling on Sensitive Bond Pads

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Glenn Carlo Miranda
Emerging designs of devices require sophisticated bond pad architecture to meet certain specifications, design applications, as well as package requirements. Sophisticated bond pad structures often have thin metal layers and POA circuit bond pads underneath which require careful application of wire bond processing to avoid cracking on the bonding pads during wire bond. Bond pad crack is one of the most detrimental issues at wire bonding, especially with POA devices, so it is important to take into consideration the wire material to be used, the process parameter to be defined, as well as the structure of the bonding pad. This paper aims to resolve and eliminate the bond pad crack by the application Initial Force via Force Profiling, whilst adhering to the output response criteria at wire bond, and not going outside the defined process parameter window. Furthermore, this paper aims to help readers to have a more comprehensive understanding of the Force parameters at wire bond, as well as the different architecture of bonding pads.

Modeling and Investigation of 3D Printing Parameters on the Melt Flow Behavior of Polylactic Acid

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Peeraphat Suttipong, Chuanchom Aumnate, Jitrawee Suk-Em, Jennarong Tungtrongpairoj
3D printing parameters such as printing temperatures and speeds play a vital role in the melt flow and printability of thermoplastic filaments in fused filament fabrication (FFF) technology. Inappropriate print settings mainly induce incomplete and poor printing quality due to melt flow instability. This research work focused on modeling the melt flow behavior of polylactic acid (PLA) at different printing temperatures and speeds using computer fluid dynamics (CFD) method. The shear stress and viscosity of PLA were investigated by a melt flow indexer (MFI) and rheometer in temperature ranges of 200 - 240 °C. A model of a capillary tube in MFI was set up with an initial condition of rheological properties from the experiment to simulate the hot melt extrusion relating to the melt flowability of PLA filaments. The high shear stress and low viscosity presented at the edge of filaments at every printing condition. Additionally, the shear stress and viscosity decreased linearly when the printing temperature increased, while the shear stress increased when the printing speed increased. The increase in shear stress caused high surface roughness of PLA specimens after printing. The findings can guide the optimization of the FFF 3D printing process to improve surface finish quality.

Application of Geopolymer Technology and Pile Raft Foundation in a Soil, Review Study

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Zaraa R. Najee, Maki J. Al Waily, Zahraa Fakhri Jawad
Foundation engineering has large challenges with weak and loose soil, especially sandy soil, which has low shear strength and high compressibility. as known used pile raft to reduced excessive settlement, differential settlement, and to increase bearing capacity of the soil to carrying the loads from super structure. The benefit of use combined (raft piles) to improved load distribution and, increase bearing capacity and enhance stability. It is depending upon many influencing factors the load distribution mechanisms, the pile number, the space between piles and on the pile position. Geopolymers are inorganic formed by the reaction of aluminosilicate materials with alkaline activator. To produce geopolymers, two essential conditions must be fulfilled: the presence of source material abundant in Silicon (Si) and Aluminium (Al), and the addition of an alkali activator, such as sodium/potassium hydroxide..it has several advantage than other traditional soil stabilization method, which increased the soil's load-bearing capacity, enhance the soil properties. This study aims to review the studies of previous researchers and their practical and theoretical findings regarding the use of geopolymers as stabilising agents and pile raft to improve the soil's resistance properties.

Enhancing the Sustainability of Road Projects Using Innovative Soil Stabilization Solutions

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Tamar Maitham Al-Asedi, Mohammed Jawad Kadhim
In order to improve the mechanical performance and sustainability of road rehabilitation operations, this research sought to examine the effects of adding sugarcane bagasse ash and polyester fibers to Babylon soil on certain geotechnical parameters. Throughout the course of the experiment, soil was amended using ash alone, with and without polyester fibers, and finally with a mix of the two additives. Particularly, the results demonstrated a considerable improvement in the soil's surface bearing capacity, unconfined compressive strength, and ideal moisture content. The maximum dry density dropped even more, as one would anticipate when dealing with less dense materials than thick soil particles. The study indicates that a 20% polyester to 15% ash ratio is the optimal ash to polyester ratio. This study adds to the growing body of information suggesting that using recycled materials might enhance soil behavior. If this holds, it may reduce environmental damage by allowing newly constructed infrastructure in areas with poor soil to be replaced with recycled materials.

Sustainability Assessment of Concrete vs. Steel Structural Systems: A Case Study on a Two-Story School Building

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Bareq Abdulhadi, Alaa Hussein Abd Ulameer, Aqeel Abdulhasan Hussein, Mustafa M. Hasan, Mohammed Abdulkarim Razouki
This study applies Life Cycle Assessment (LCA) using OpenLCA software in accordance with ISO 14040/14044 standards. A two-story school building was modeled with reinforced concrete and structural steel systems, both designed using ETABS. The study looks at a two-story school building over several phases, such as getting materials, making them, building them, using them, and then getting rid of them. Key performance indicators such as carbon emissions, energy consumption, recyclability, and construction waste are analyzed. Results reveal that concrete structures emit 27% less CO₂ and consume 55% less energy than steel systems, though steel offers superior recyclability (98%). The results show that steel structures may be recycled and used again and again, whereas reinforced concrete uses substantially less energy and carbon. The study proposes the use of hybrid systems that combine concrete slabs and foundations with steel superstructures to actualize these results. It also proposes employing materials that are good for the environment, such fly ash and recycled aggregates, and establishing national databases to assist people choose products. These suggestions are a practical way to get Iraq to embrace green building laws and practices.

Structural Damage Prediction of a Concrete and Steel Bridge Using Acceleration Signal Processing and Artificial Intelligence Algorithms

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Nicole Xiomara Diaz, Aldahir William Ortega, Rick Milton Delgadillo
This study presents a methodology for predicting structural damage in a concrete and steel bridge using acceleration signal processing and artificial intelligence techniques. Structural vibrations were recorded continuously for 24 hours using five LARA (Low-cost Adaptable Reliable Anglemete) triaxial sensors located on the metal beams under the bridge, capturing data in three axes. The signals were normalized in order to be able to have a fairness of accelerations in the 3 axes and processed through a Convolutional Autoencoder (CAE), which achieved a signal reconstruction fidelity of 97.22%, enabling the generation of realistic synthetic data. To evaluate the separability between real and synthetic signals, a Domain-Adversarial Neural Network (DANN) was applied, successfully classifying both domains. Subsequently, K-Means clustering was performed on the compressed latent space, identifying three distinct structural states: healthy, transitional, and anomalous, with a silhouette coefficient of 0.8947. Notably, Sensors 2 and 4 were grouped into the anomalous cluster, indicating potential localized structural degradation. Finally, a Temporal Convolutional Network (TCN) was implemented to predict the future structural condition based on sequences of latent features. The model achieved an overall accuracy of 85.29% and an F1-score of 0.9954 for transitional states, demonstrating its effectiveness in anticipating early structural changes and reinforcing the potential of the proposed methodology for real-time, predictive bridge monitoring applications.

Welding Procedure Effect on the Hydrogen Diffusion Behavior and Hydrogen Embrittlement Susceptibility of Welded Joint for Hydrogenation Reactor

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Guang Xu Cheng, Wei Chen Song, Song Yan Hu, Sheng Wen Tu, Hai Jun Hu
This study employs hydrogen permeation tests, slow-strain-rate tensile tests, and Charpy impact tests to investigate how the welding process and PWHT influence hydrogen diffusion behavior and hydrogen embrittlement susceptibility of welded joint. The research results indicate: The microstructure of all regions of the welded joint consist of granular bainite, MA islands, and precipitated carbides, carbides are mainly M23C6, M7C3, M2C, and M6C types. These carbides act as irreversible hydrogen traps and are the primary reason for the reduced hydrogen diffusion coefficient in the material. The heterogeneous microstructure of the weld metal causes direction-dependent hydrogen diffusivity. PWHT also influence hydrogen embrittlement susceptibility. The findings of this study can provide theoretical guidance for optimizing welding procedures in the fabrication of hydrogenation reactors.

Geological, Geophysical and Hydrological Controls on Sinkhole Formation in Saudi Arabia: Linking Karst Processes to Anthropogenic Impacts

Mon, 13 Apr 2026 00:00:00 +0200

Publication date: 13 April 2026
Source: Applied Mechanics and Materials Vol. 935
Author(s): Ayman N. Qadrouh, Samiya Alkhairy, Khalid S. Aldamegh, Mansour Alotaibi, Saleh S. Esshily, Abdulrhman H. Alghamdi, Mazen M. Alyousif
This study addresses the increasing occurrence of sinkholes in northern and eastern Saudi Arabia, driven by soluble karst geology and unsustainable groundwater extraction. The primary objective is to understand the underlying mechanism of sinkhole formation and propose targeted mitigation strategies. By integrating geological, geophysical (ERT, GPR, microgravity), and hydrological data from previous studies, the research identifies key subsurface features and groundwater conditions contributing to sinkhole development. The results reveal that sinkhole formation is primarily governed by cover-collapse processes, strongly associated with aquifer over-extraction, low-resistivity anomalies, and irrigation-induced saturation. Groundwater declines of 2.5–3 m/year, along with acidic and saline conditions, further accelerate karst dissolution. The study concludes with a three-part mitigation framework: sustainable groundwater management, engineered stabilization of high-risk cavities, and an integrated early-warning system using geophysical monitoring and InSAR. These findings offer a practical roadmap for managing sinkhole hazards in arid karst environments.