Helio Matos

University of Rhode Island | URI · Department of Mechanical, Industrial and Systems Engineering

A series of experiments is conducted to study energy transfer in a chain of foam disks as a function of temperature. These experiments use two different densities of closed-cell Polyvinyl Chloride foams as an array. A puncture testing machine impacts the chain at a velocity of 1 m/s at five different temperatures. Piezoelectric sensors capture the...

Polymeric composite sandwich materials are critical for marine structures, but their behavior under near-field underwater explosions is not well understood. This study investigates the dynamic response of carbon-fiber-reinforced sandwich composites with varying core densities subjected to near-field underwater explosions. Lab-scale experiments were...

Multifunctional composites and smart textiles are an important advancement in material science, offering a variety of capabilities that extend well beyond traditional structural functions. These advanced materials are poised to revolutionize applications across a wide range of industries, including aerospace, healthcare, military, and consumer elec...

The implosion of underwater composite structures is a critical and complex engineering problem, necessitating high-strength, lightweight, and corrosion-resistant materials for deep-sea applications. This manuscript reviews the intricate failure mechanisms of composite structures, focusing on cylindrical structures under extreme underwater condition...

This study explores an optimization system to achieve the highest collapse pressure on glass-carbon hybrid composite cylinders under hydrostatic loading conditions. This work evaluates and validates previously established composite buckling solutions for cylindrical composite structures under hydrostatic pressure with experimental results of hybrid...

In this study, damage mechanisms and the piezo-resistance response of glass/carbon intralaminar hybrid composites are examined under blast loading conditions. Two-ply orientations are considered, namely a repeating ((G45C45)R) and an alternating ((G45C45)A) +/− 45° glass/carbon layers, along with three boundary condition configurations: simply supp...

Underwater explosions are inherently complex and unique physical phenomena markedly distinct from those occurring above the surface. This distinctiveness is primarily attributed to the relatively incompressible nature of water, which fundamentally alters the propagation and impact of shock waves. The study of underwater explosions is paramount in a...

Background The vulnerability of polymeric composite sandwich structures in marine applications to air explosions highlights a significant gap in our understanding of the dynamic behavior of the curved sandwich structures, which is essential for design improvements. Objective This study aims to explore the dynamic response and failure mechanisms of...

This paper investigates the electromechanical performance of textile fabric with conductive yarn elements for data transmission capabilities. Electromechanical experiments were conducted to evaluate the electrical response of copper yarn elements stitched axially to the textile fabric, while assessing the mechanical response of the system during te...

This research arises from the concern of damage to submersible marine structures such as underwater vehicles and pipelines and the need to understand dynamic failure. This work focuses on analyzing the dynamic bubble-to-structure interaction of curved metallic plates subjected to air-backed underwater explosive loading. This work aims to expand the...

An experimental investigation was performed on an artificial human lung to evaluate its response and behavior after being subjected to an underwater explosive blast. The experiments were performed using a 63 mg TNT equivalent explosive charge placed 0.5 m from the front of the lung. The specimen used was a to-scale lung model representative of a 50...

This study experimentally investigates the failure behavior of 3D-printed polymer tubes during underwater implosion. Implosion is a prevalent failure mechanism in the underwater domain, and the adaptation of new technology, such as 3D printing, allows for the rapid manufacturing of pressure vessels with complex geometries. This study analyzes the f...

This study evaluates the performance of composite structures with embedded conductive yarns during shock loads to create a multifunctional system for immediate failure detection. The scalable sensing yarns were made by braiding Kevlar fibers with Nitinol fibers and then integrating them into a carbon/epoxy prepreg. The multifunctional structure was...

This study investigates the long-term performance of 3D-printed pressure vessels subjected to accelerated aging through water mass infusion. Thermoplastic composites were used to construct the pressure vessels using Material extrusion 3D printing, and subsequent submersion in an ocean water solution at elevated temperatures was employed to simulate...

Experiments were conducted to investigate the dynamic buckling behavior of underwater hybrid composite tubes. The study focused on roll-wrapped hybrid layered glass-carbon fiber epoxy composite shells with a six-layer quasi-isotropic layup configuration. In addition to control specimens consisting of fully glass fiber-reinforced polymer and carbon...

An experimental investigation was performed on human lung simulants to evaluate their response to an underwater explosive blast. The artificial lungs were instrumented with sensors to record changes in the internal pressure and strains for a specimen with and without a surrounding ribcage. The lungs were to-scale models representative of a 50th-per...

Metamaterials have received extensive attention in fundamental and applied research over the past two decades due to their unique mechanical behavior. This paper presents an interpretable machine learning (ML) approach for efficient response prediction of three-dimensional (3D)-printed metamaterials. However, developing such an ML-based model requi...

Background This research arises from the concern of damage to submersible marine structures such as underwater vehicles and pipelines and the need to understand dynamic failure. This work focuses on analyzing the dynamic bubble-to-structure interaction of curved metallic plates subjected to air-backed underwater explosive loading.Objective This res...

An experimental study was performed to analyze the dynamic buckling behavior of stiffened composite tubes. The structures analyzed were filament-wound carbon-fiber/epoxy composite tubes with press-fitted compliant and rigid aluminum ring stiffeners. The ring thicknesses were chosen for a consistent buckling pressure for equally spaced one, two, and...

This study evaluates the power transmission of multifunctional composites with embedded conductors. The electrical conductors were constructed by braiding copper strands with Para-aramid fibers into a tape configuration, then placing these tapes within carbon/epoxy prepregs to create a multifunctional structure. Experiments were performed on these...

This study investigates the effects of 3D-printed thermoplastics' long-term exposure to ocean water. The work focuses on seawater diffusivity rates and mechanical performance to discuss material candidates for long-term undersea structures. Several commonly available thermoplastics were printed using Fused Deposition Modeling and then submerged in...

Deep-sea structures will collapse/implode under hydrostatic pressure when the structure dives below a threshold, leading to structural instability and catastrophic failure. To better understand how the layup angle of composite cylindrical shells influences this instability threshold, the present work explores how composite cylinders can achieve the...

The interaction between structures and bubbles generated by an underwater explosive (UNDEX) has been experimentally and computationally investigated. The problem analyzed consists of a flat steel plate adjacent to an explosive within an underwater environment. The experiments were performed for different standoff distances using high speed photogra...

Polymer-based sandwich composites have found increasing applications in the marine industry, where they are at an ever-increasing risk of encountering high-intensity underwater (UNDEX) or in air (AIREX) explosive loading. This review presents the current state of the art in achieving adequate blast mitigation, employing polymeric composites. An att...

An experimental and computational investigation was conducted to study the interaction between bubbles generated by an underwater explosive (UNDEX) and a nearby steel plate structure. The experiments were performed for different standoff distances to investigate the interaction between the gas bubble and the rigid structure. High-speed photography...

This study presents closed-form solutions for the critical buckling pressures and characteristic frequencies of underwater composite cylinders. The analytical solutions were derived using the full stiffness definitions from composite laminate theory, making them suitable for symmetric, asymmetric, hybrid, and/or double-shell (sandwich) cylindrical...

A review of some recent advancements in knowledge of composite shell and sandwich structures subjected to extreme loading conditions in complex air and underwater environments is presented. Studies include polyurea (PU) coatings for mitigation of the response of these structures. Composite structures subjected to in-air blast loading included E-Gla...

The underwater collapse mechanics of environmentally degraded filament-wound Carbon-Epoxy composite tubes were investigated in this study. The composite tubes were submerged in an elevated temperature saline water solution for 35 and 70 days. The temperature of the saline bath was held at 65 °C, in which case the 35 and 70 days duration simulates 3...

An experimental and computational study was conducted to evaluate the dynamic response of weathered biaxial composite plates subjected to near-field explosive/blast loadings. Naval structures are subjected to aggressive marine environments during their service life that can significantly degrade their performance over time. The composite materials...

The Murray Lecture that was delivered in 2011 included a historical perspective on salient features of research conducted and published by Arun Shukla. A review of experimental work since the Murray Lecture is presented in this paper on the topic of imploding underwater structures. Specifically, the dynamic underwater collapse of metallic structure...

An experimental study was conducted to evaluate the response of weathered unidirectional composite plates subjected to near-field blast loading. The composite materials in this study are carbon-epoxy composite plates with a [45, −45]s layup and was subjected to simulated marine aging through submersion in seawater baths for 70 days at 65 degrees Ce...

An experimental study was conducted to investigate the energy mitigation of hydrostatically initiated implosions of composite and metallic structures. Energy mitigation is achieved by placing polyurea coatings of different thicknesses at different locations onto imploding structures. The implodable structures are made of AL 6061-T6 and carbon-fiber...

This study experimentally investigates fluid structure interactions occurring during confined implosions using high-speed digital image correlation (DIC). Aluminum tubular specimens are placed inside a confining cylindrical structure with one end open to a pressurized environment. These specimens are exposed to hydrostatic pressure, which is slowly...

An experimental study is conducted to investigate the dynamic response and instability of cylindrical structures subjected to hydrostatic pressure in conjunction with explosive loading. Full-field displacements/velocities, and localized pressures, of imploding aluminum structures within a confining environment are captured during the experiments. A...

The impact force loss behavior of flocked energy absorbing materials (FEAM) was experimentally studied in the context of double-side flocked FEAM element layered structures. A ball drop test determined the force loss per cent (FL%) properties of various assembled panels. This study showed that: (a) FEAM layers are most effective when used in multip...

This study aims to develop an experimental scheme to determine the localized energy emitted during the dynamic collapse of aluminum structures. Upon collapse, these structures release damaging pressure pulses into the surrounding fluid; to mitigate this effect, the structures are coated with polyurea. The new energy scheme is used to analyze the en...

The fluid structure interaction phenomenon occurring in confined implosions is investigated using high-speed three-dimensional digital image correlation (DIC) experiments. Aluminum tubular specimens are placed inside a confining cylindrical structure that is partially open to a pressurized environment. These specimens are hydrostatically loaded unt...

An experimental investigation to understand the mechanisms of dynamic buckling instability in cylindrical structures due to underwater explosive loadings is conducted. In particular, the effects of initial hydrostatic pressure coupled with a dynamic pressure pulse on the stability of metallic cylindrical shells are evaluated. The experiments are co...

An experimental study on the underwater buckling of composite and metallic tubes is conducted to evaluate and compare their collapse mechanics. Experiments are performed in a pressure vessel designed to provide constant hydrostatic pressure through the collapse. Filament-wound carbon-fiber/epoxy, glass/polyester (PE) tubes, and aluminum tubes are s...