Mechanical Engineering Commons^™

Enhancing Bridge Resilience And Overheight Vehicle Mitigation Through Innovative Sacrificial Cushion Systems, Aly Mousaad Aly, Marc Hoffmann

Faculty Publications

Transportation departments have made significant strides in addressing the challenges posed by the increasing weights of trucks on bridges. While there is a growing awareness of overheight vehicle collisions with bridges, implementing effective countermeasures remains limited. The susceptibility of bridges to damage from such collisions is on the rise, further exacerbated by unpredictable lateral impact forces. This study employs nonlinear impact analysis to assess the response of an unprotected vehicle-girder model, yielding realistic deformation outcomes comparable to observed impacts on the US-61 bridge. Predictions for a truck traveling at 112.65 km/h indicate deformations of 0.229 m, 0.161 m, and 0.271 …

Railroad Condition Monitoring Using Distributed Acoustic Sensing And Deep Learning Techniques, Md Arifur Rahman

Electronic Theses and Dissertations

Proper condition monitoring has been a major issue among railroad administrations since it might cause catastrophic dilemmas that lead to fatalities or damage to the infrastructure. Although various aspects of train safety have been conducted by scholars, in-motion monitoring detection of defect occurrence, cause, and severity is still a big concern. Hence extensive studies are still required to enhance the accuracy of inspection methods for railroad condition monitoring (CM). Distributed acoustic sensing (DAS) has been recognized as a promising method because of its sensing capabilities over long distances and for massive structures. As DAS produces large datasets, algorithms for precise …

Isolation And Characterization Of Caffeine-Degrading Bacteria From Coffee Plantation Areas In Malaysia, Elvina Clarie Dullah, Mohd Fazli Farida Asras

Makara Journal of Technology

Decaffeination by microbial degradation is currently the most optimal and low-cost approach, involving only microbial cells and/or their enzymes. The bacterium was characterized using a series of biochemical tests. Positive results were obtained from carbohydrate fermentation, citrate utilization, and catalase tests, while negative results were obtained from Voges-Proskauer (VP) and indole tests. Three different caffeine concentrations of 0.25%, 0.4%, and 2% were tested and measured through Gas Chromatography-Mass Spectrophotometry (GC-MS) analysis. The highest caffeine reduction (89.25%) was found when 0.25% caffeine was used in the media. Only a small amount of caffeine was reduced to 0.4% and 2%, with 34.78% …

Optimization Of The Building Envelope And Roof Shading To Reduce The Energy Consumption Of College Low-Rise Buildings In Indonesia, Nasruddin Nasruddin, Azimil Gani Alam, Mohammad Imroz Sohel

Makara Journal of Technology

Energy consumption in buildings is a crucial concern globally, prompting researchers to explore innovative solutions to mitigate its impact. This study investigates the optimization of building envelopes and roof shading systems of existing buildings in Indonesia to realize notable energy savings. Multiple scenarios were explored, with modifications to building envelopes and roof shading, highlighting the overall thermal transfer value as a key parameter. Using EnergyPlus simulations, the efficacy of natural ventilation in corridors and roof shading modifications was assessed in reducing energy consumption. The findings revealed that renovating existing buildings by optimization of the building envelope and roof shading by …

Modular Composite Sandwich Structures For Thermal And Structural Retrofitting Of Existing Buildings, Marc Al Ghazal

Masters Theses

Around 40% of global energy consumption and 30% of worldwide carbon dioxide (CO2) emissions are attributed to buildings. Most of this consumption is dedicated to ensuring thermal comfort. The goal of this research was to develop and field validate retrofit solutions to improve the energy efficiency of buildings. Exterior cladding panels were designed and tested to ensure adequate thermal and structural performance. Sandwich panels (glass fibers reinforced polymer (GFRP) skins and polymeric foam cores) were fabricated using the vacuum assisted resin transfer molding (VARTM) process. Extruded polystyrene (XPS) and polyurethane (PU) foams were compared as core materials through a series …

Ai-Based Bridge And Road Inspection Framework Using Drones, Hovannes Kulhandjian

Mineta Transportation Institute Publications

There are over 590,000 bridges dispersed across the roadway network that stretches across the United States alone. Each bridge with a length of 20 feet or greater must be inspected at least once every 24 months, according to the Federal Highway Act (FHWA) of 1968. This research developed an artificial intelligence (AI)-based framework for bridge and road inspection using drones with multiple sensors collecting capabilities. It is not sufficient to conduct inspections of bridges and roads using cameras alone, so the research team utilized an infrared (IR) camera along with a high-resolution optical camera. In many instances, the IR camera …

Challenges In Optimization For The Performance On Sustainability Dimensions In Reverse Logistics Social Responsibility, Sumarsono Sudarto, Katsuhiko Takahashi, Mochammad Dewo

Makara Journal of Technology

Reverse logistics social responsibility is preferred as the most acceptable solution for addressing the challenges in stakeholders’ debate regarding social responsibility in supply chains because it involves as many actors as possible in the supply chain to perform social responsibility to achieve sustainability. This paper explores the challenges in achieving optimal policies in sustainability dimensions for collection and recycling facilities in reverse logistics. Sustainability dimensions include economic, environmental, and social aspects. The reverse logistics is modeled on System Dynamics, and a simplified statistical analysis using a contour chart is employed in numerical experiments. Results show a narrow area of optimal …

Investigating The Effect Of Bead Geometry On Fiber Orientation And Thermomechanical Properties For Large-Format Extrusion-Based Additive Manufacturing, Joanna F. Keaton

Electronic Theses and Dissertations

In large-format extrusion-based additive manufacturing of polymer composites, the relationship between material properties and processing parameters requires further investigation. This thesis focuses on the relationship between fiber orientation and thermomechanical properties for short fiber-filled thermoplastic polymer systems manufactured by extrusion-based additive manufacturing. Fiber orientation is particularly important in determining the thermomechanical properties of the composite material as properties in the direction of deposition are expected to be higher for highly aligned fibers than randomly aligned fibers. Fiber orientation distribution, which is related to processing parameters and deposition conditions, can be efficiently represented by the orientation tensor. The orientation tensor can …

The Effects Of Hurricane Wind Field Characteristics On Wind Blade Loads, Michael S. Tsai

Masters Theses

Over recent years, offshore wind energy has been growing around the world. This necessitates placing wind turbines directly in or near the oceans where hurricanes can be. Previous research has suggested that hurricane wind veer and direction change can have adverse loading effects on the turbine. Such effects can create damage to the blade or worsen existing ones. Currently, there is no known design standard for addressing wind veer and direction change specifically from hurricanes. Quantifying the loading contribution from these phenomena is not abundant either.

This thesis seeks to demonstrate a proposed procedure for defining design veer profiles and …

Vibration Fatigue Of Leaded Solder Joint Interconnects For Pcb Electronics, John Crowder

All Theses

With the increasing prevalence of electronic equipment worldwide, there is also a decrease in the size of the components on their printed circuit boards (PCBs), leading to an increase in the density of these components. A significant amount of failure in electronic equipment is vibration fatigue of solder joints and their attachments. However, the complexity of these PCBs and their components has made finite element modeling (FEM) more complex, adding considerable time to create and analyze a model.

This paper aims to provide a literature review for the vibration fatigue of leaded solder components, create a test setup, and validate …

The Center For Centering Dome, Olek Piechaczek, Ryan M. Scharf

Architectural Engineering

The Center for Centering seeks to create a large-scale healing center, conducive to individual centering of the mind and body. This mobile installation provides a relaxing, enclosed space while still maintaining a connection to the outdoors. The clients liked the idea of having a pop-up installation that could be easily set up as a touring display. With a deadline for installation looming in June 2022, a team of students had five months to design and manufacture the structure.

In winter 2022, the students developed custom geometry to minimize the number of individual parts and built a ¼ scale model of …

Using Bim To Increase The Efficiency Of Energy-Driven Retrofitting Projects, Anne Grego, Shannon Chance, Barry Mcauley

Conference Papers

The building sector is responsible for nearly 40% of global energy consumption. Many existing buildings have poor thermal insulation and low energy performance, hindering sustainability goals. Energy-driven building retrofitting could address this issue and implementing Building Information Modelling (BIM) in retrofitting can reduce process time, costs, and waste associated with such undertakings. Yet, there is a lack of research and insufficient guidance for implementing BIM in energy-driven retrofitting. A BIM framework is presented to enhance decision-making processes during retrofitting. The aims of this study were to (1) identify BIM technologies and methodologies that could address existing barriers and improve efficiency …

Efficient Sintering Of Lunar Soil Using Concentrated Sunlight, Diprajit Biswas

Electronic Theses and Dissertations

Construction material is one crucial need for long-term habitation on the moon. When concentrated for high heat flux, solar radiation can heat lunar soil or regolith until it sinters at temperatures above 900°C. The solid, sintered soil simulant can be used as construction material. This work explores the conditions leading to effective lunar soil sintering for both direct and indirect irradiated sintering. Lunar soil simulants were sintered using concentrated light from a xenon-arc lamp with varying heat flux intensity. During direct sintering of LHS-1, a sintering range of 860°C-1140°C corresponding to a peak heat flux of 105-120 kW/m2 was identified …

Mechanics And Mechanisms Of Fracture For An Eastern Spruce Subject To Transverse Loading Using Acoustic Emission, Parinaz Belalpour Dastjerdi

Electronic Theses and Dissertations

Due to its excellent structural qualities and accessibility, wood is among the most often utilized structural materials. Despite its ubiquity, wood poses numerous challenges. It is heterogeneous and anisotropic. It has a complex hierarchical ultrastructure, and the properties can have wide variation within a species, and indeed within an individual tree. This work aims to improve our understanding of the strength and fracture behavior of spruce-pine-fir (south) (SPFs), particularly in cross-grain direction. This study’s primary goal is to examine the relationship between crack propagation and cross grain morphology under the following loading configurations: compact tension, compression, and rolling shear. The …

Machine Learning-Based Data And Model Driven Bayesian Uncertanity Quantification Of Inverse Problems For Suspended Non-Structural System, Zhiyuan Qin

All Dissertations

Inverse problems involve extracting the internal structure of a physical system from noisy measurement data. In many fields, the Bayesian inference is used to address the ill-conditioned nature of the inverse problem by incorporating prior information through an initial distribution. In the nonparametric Bayesian framework, surrogate models such as Gaussian Processes or Deep Neural Networks are used as flexible and effective probabilistic modeling tools to overcome the high-dimensional curse and reduce computational costs. In practical systems and computer models, uncertainties can be addressed through parameter calibration, sensitivity analysis, and uncertainty quantification, leading to improved reliability and robustness of decision and …

Wind-Wave Misalignment Effects On Multiline Anchor Systems For Floating Offshore Wind Turbines, Doron T. Rose

Masters Theses

Multiline anchors are a novel way to reduce the cost of arrays of floating offshore wind turbines (FOWTs), but their behavior is not yet fully understood. Through metocean characterization and dynamic simulations, this thesis investigates the effects of wind-wave misalignment on multiline anchor systems. Four coastal U.S. sites are characterized in order to develop IEC design load cases (DLCs) and analyze real-world misaligned conditions. Stonewall Bank, Oregon showed the highest 500-year extreme wave height, at 16.6 m, while Virginia Beach, Virginia showed the highest 500-year wind speed, at 56.8 m/s. Misalignment probability distributions, at all sites, are found to converge …

Elevation-Distributed Multistage Reverse Osmosis Desalination With Seawater Pumped Storage, Hani E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

A seawater reverse osmosis (RO) plant layout based on multistage RO with stages located at different elevations above sea level is described. The plant uses the weight of a seawater column from pumped storage as head pressure for RO (gravity-driven multistage RO) or to supplement high-pressure pumps used in RO (gravity-assisted multistage RO). The use of gravitational force reduces the specific energy for RO compared to using high-pressure pumps. By locating the RO stages at different elevations based on demand sites, the total specific energy consumption for RO and permeate transport to different elevations above sea level is reduced from …

Damage Stability Study Of A 500 Dw Ro-Ro Ferry Vessel, Zulfaidah Ariany, Budhi Santoso, Sarwoko Sarwoko, Nauval Abdurrahman Prasetyo

Makara Journal of Technology

The development of the crossing transportation industry is currently increasing in the island areas. The use of Ro-Ro type ferry boats is extremely efficient in moving people, goods, and vehicles. The current research focuses on the damage stability of the 500 DWT Ro-Ro ferry, which aims to meet the needs of the Ro-Ro ferry in the archipelago area. The previously existing initial design of a barge hull with a main size Lpp = 40.15 m, B = 12 m, H = 3.2 m, and T = 2.15 m was used to analyze the damage stability condition further. First, the drawings …

Energy Dissipation In A Sand Damper Under Cyclic Loading, Ehab Sabi

Civil and Environmental Engineering Theses and Dissertations

Various seismic and wind engineering designs and retrofit strategies have been in development to meet structures' proper and safe operation during earthquake and wind excitation. One such method is the addition of fluid and particle dampers, such as sand dampers, in an effort to reduce excessive and dangerous displacements of structures. The present study implements the discrete element method (DEM) to assess the performance of a pressurized sand damper (PSD) and characterize the dissipated energy under cyclic loading. The idea of a PSD is to exploit the increase in shearing resistance of sand under external pressure and the associated ability …

Use Of Precious Plastic Method Of Bricks For The Construction Of Tiny Homes, Haylie E. Tallon

Architectural Engineering

Precious Plastics, a Netherlands based company, created an open source project that can be used to create different objects from recycled plastics. The San Luis Obispo area has a large amount of recyclable plastic that is being treated as trash, adding to the pollution of the ocean and the air. This project is to determine the necessary steps to create plastic building blocks, using the Precious Plastic process, as a construction material for low-income, temporary housing. This report covers the process that was used to build two of the machines that will be used to create the bricks. This requires …

Evaluation Of Material Request Order To Support Sustainable Construction, Fajar Susilowati, Nur Nahdiah Anggraeni

Makara Journal of Technology

This study was conducted on one of Indonesia’s apartment projects, in which reinforced concrete is the main structure. Based on existing project data, this project experienced a decline in the construction work’s progress, thus reducing the project’s overall progress. This decline occurred because the delivery of concrete reinforcement material was delayed. This study aimed to determine the process of material request order and its relationship with the work implementation, as well as the factors that influenced the delayed arrival of concrete reinforcement material at the project site. The method used in this study was observation and interview. Data were analyzed …

Structural Dynamics Of Awt-27 Wind Turbine Blade, Amr Ismaiel

Future Engineering Journal

Wind energy is one of the world’s current leading renewable energy resources. One of the major aspects of studying wind turbines is the structural dynamics for the turbine structure including blades and support structure. In the current work, the blades of the Advanced Wind Turbine (AWT-27) are investigated in a dynamic approach. Different wind fields have been generated for the study to provide different Design Load Conditions (DLCs). Three laminar wind velocities of 5 m/s, 12 m/s, and 17 m/s were simulated. Turbulent wind flow fields have also been generated at the three standard classes A, B and C of …

Shallow-Water Wind Turbine Foundation, Andrew Walker, Nico Nani, James Cusanelli, Zachary Dunkelberger

Mechanical Engineering

Over the 2021-2022 academic year, we, the Shallow Water Wind Turbine Foundation senior project team, designed, manufactured, and tested a fixed bottom, sand mounted turbine foundation for the Cal Poly Wind Power Club’s Collegiate Wind Competition turbine. The foundation was restricted to certain material, installation, and geometric constraints outlined in this report, and needed to support the turbine under operating conditions including 22 m/s wind speeds. The design was analyzed using primarily a bearing capacity geotechnical analysis to determine final geometry and weight. The foundation was then manufactured using welded, custom carbon steel parts.

The foundation was inspected for geometric …

Joining Methods For Continuous Fiber Reinforced Thermoplastic Composites In Structural Applications, Andrew Moran

Electronic Theses and Dissertations

Continuous fiber reinforced thermoplastic (CFRTP) composites have been proposed as an alternative to metals in structural applications. CFRTP composites can be used to create structures that are lighter weight, have better resistance to environmental factors, and have the potential to be recycled. However, one of the main challenges to CFRTP composites is connections between structural members. The goal of this thesis is to investigate the feasibility of joining CFRTP composites to both similar and dissimilar materials through literature review, coupon testing, design of a structural joint, and a small scale laboratory prototype of the joint. To achieve this goal the …

Strain-Based Design Of Steel-Polymer-Steel Composite Pipes, Vul Thang

University of New Orleans Theses and Dissertations

Many offshore single-wall pipelines and structural failures have occurred in the past. As a result, lives were lost, and billions of dollars were spent. In addition, natural disasters such as earthquake fault zones can cause a large volume of soil movement. This can easily damage single-wall pipelines or piles of fixed offshore platforms in the earthquake fault zone.

Currently, the single-wall pipelines are used for the offshore and onshore oil and gas industry. This research investigated the use of double-wall composite pipe steel-polymer-steel (SPS) in place of single-wall pipe to prevent such failures. The double-wall composite pipe has a larger …

Development Of Thermoplastic Composite External Reinforcing Of Concrete Decking System, Jackman A. Mickiewicz

Electronic Theses and Dissertations

The use of reinforced concrete is very common in the construction of a wide variety of structures. In buildings it is used for floors, beams, columns, and walls. It can also be used in infrastructure as parts of bridges, dams, pavements, etc. Typically, concrete is reinforced with steel, primarily rebar, to carry tensile stresses.

Like every other industry, construction is always looking at ways to advance its technology. The work outlined in this thesis looks to assist in that goal, primarily by looking at options for using a different material than the traditional steel reinforcements to create a reinforced concrete …

Enhancement Of Biogas Production Through Solid-State Anaerobic Co-Digestion Of Food Waste And Corn Cobs, Lukhi Mulia Shitophyta, Anisa Salsabila, Firanita Angraini Putri, Siti Jamilatun

Makara Journal of Technology

Although biogas has been primarily produced through liquid anaerobic digestion, this method leads to the floating and stratification of fibers and non-homogeneous mixing, which can reduce the biogas yield. Alternatively, biogas can be produced by the solid-state anaerobic digestion (SS-AD) of organic material with a high solid content, such as corn cobs. We investigated the co-digestion of food waste and corn cobs as a biomass feedstock for SS-AD in biogas production. We measured the effects of the total solid (TS) content, percentage of food waste, and reduction in volatile solids (VS), from which we determined its appropriate kinetic model. We …

Control Strategy For Solar Energy-Saving Lamps For Optimized Energy Utilization And Sustainability Of Operation Durability: Indonesia Case, Burhanuddin Halimi, Agus Purwadi, Nana Heryana

Makara Journal of Technology

To solve the electrification ratio issue, the Indonesian government has promoted the use of solar energy-saving lamps. This study proposes a control strategy that adopts current reference time-based profiling for solar energy-saving lamps. For optimal energy consumption, the current reference profile is determined according to users’ daily energy requirements. From the aspect of user comfort, a gradual step reference profile is also introduced to provide a subtle change in lighting intensity level. The proposed control strategy can minimize energy consumption and optimize the operation durability of the system. The concept is verified by simulating four scenarios, the results of which …

A Case Study Of Protecting Bridges Against Overheight Vehicles, Aly Mousaad Aly, Marc Hoffmann

Faculty Publications

Most transportation departments have recognized and developed procedures to address the ever-increasing weights of trucks traveling on bridges in service today. Transportation agencies also recognize the issues with overheight vehicles’ collisions with bridges, but few stakeholders have definitive countermeasures. Bridges are becoming more vulnerable to collisions from overheight vehicles. The exact response under lateral impact force is difficult to predict. In this paper, nonlinear impact analysis shows that the degree of deformation recorded through the modeling of the unprotected vehicle-girder model provides realistic results compared to the observation from the US-61 bridge overheight vehicle impact. The predicted displacements are 0.229 …

Thermal And Mechanical Numerical Modeling Of Extrusion-Based 3d Printed Reinforced Polymers For Selecting Manufacturing Process Parameters, Sunil Bhandari

Electronic Theses and Dissertations

Extrusion-based 3D printing of thermoplastic polymer composites manufactures parts that have nonhomogenous, orthotropic, and process-dependent macro-scale material properties. As a part of the dissertation, research works were carried out to: • improve the interlayer mechanical properties and reduce the orthotropy, • use experimentally homogenized orthotropic material properties to numerically model the mechanical behavior of the non-homogenous orthotropic 3D printed parts, • create an efficient numerical thermal model to predict the process-dependent thermal history of the 3D printed part, and • aid the manufacturing process by selecting a suitable set of processing parameters based on a simplified sequentially coupled thermomechanical model. …