Leslie Lamberson

Colorado School of Mines · Department of Mechanical Engineering

As the number of orbital structures increases, so does the threat posed by micrometeoroid and orbital debris (MMOD) impacts. These impacts range from the ballistic range (less than 1.5 km/s) to exceeding 20 km/s and can significantly weaken space structures such as the International Space Station (ISS), leading to further risk as the debris shed co...

An experimental apparatus for measuring the dynamic behavior of materials subjected to strain rates on the order of 10 $$^3$$ 3 s $$^{-1}$$ - 1 and temperatures up to 800°C with a unique triple actuation system is developed in this work. This system is based on the traditional Kolsky (or split-Hopkinson pressure) bar design, with the addition of an...

This study examines the fracture behavior of two thermosetting polymer resins for additive manufacturing (AM) and specifically presents the role of print orientation on the quasi-static and dynamic fracture responses of DA-3 resin printed via digital light processing (DLP) and PM-EM828 resin printed via stereolithography (SLA). A unique long-bar ap...

Many energy absorption applications utilize flexible polymeric foams for their viscoelastic properties. It is desired that the material will perform consistently across repeated compression cycles. This study examines the effect of fatigue at low strain rates on the viscoelasticity of open‐cell polyurethane foam. Six polyurethanes of the same base...

Polymers find widespread use in applications where they are subjected to impact loading. Therefore, understanding the time dependence of their mechanical response is critical to the design of structures subjected to these high strain rate environments. However, characterising these materials on microsecond time scales has proven challenging. Tradit...

Background Polyurethane foams have many uses ranging from comfort fitting seats and shoes to protective inserts in helmets and sports equipment. Current military helmet designs employ foam pads of varying densities and bulk material properties to help absorb energy from impacts ranging from quasi-static to ballistic level strain-rates. Objective T...

The number of threats to space structures due to micrometeoroid and orbital debris (MMOD) impact continues to increase as the density of structures in orbit increases. Upon impact from (MMOD), the structure will have significantly reduced strength, however additionally; the debris shed post-impact causes a compounding risk of damage to the in-orbit...

Fiber-reinforced composites subject to low-energy repeated impacts can result in subsurface damage that affects their structural integrity. This paper presents a non-destructive damage evaluation technique for carbon-fiber reinforced polymers (CFRP) using the virtual fields method (VFM). Repeated impacts with an energy of 2 J were performed on 8-pl...

Hypervelocity impact cratering by asteroids and comets is one of the most common geological processes in the solar system. Investigations of the cratering process can be used to characterize the physical attributes of planetary surfaces and interiors, and to understand solar system evolution. Fundamental parameters including density, mass, and macr...

The service life of aircraft structural components often experience sub-catastrophic impact events, such as during launch and landing cycles or blunt impacts from ground service equipment. These occurrences lead to impact fatigue that can result in damage of the carbon fiber-reinforced composite structural components (CFRCs). Due to their stacked l...

Composite structures used in aerospace, automotive, and military applications are often subjected to aggressive marine or water environments during their service life that can cause material degradation over time. Many composites absorb moisture when exposed to wet environments which may affect their microstructure, consequently influencing their b...

This study investigates the water saturation effects on the dynamic compressive strength and fragmentation behavior of Indian gabbronorite. A selection of gabbronorite was divided into specimens that were either saturated in distilled water for 120 days or dried in a vacuum oven at \(105\,\,^\circ\)C. The specimens were then compressed to failure a...

Coupon specimens of poled and depoled lead zirconate titanate (PZT) are examined under combined stress wave and electric loading conditions. Mode‐I crack initiation and fracture behavior is examined using ultrahigh‐speed imaging and two‐dimensional digital image correlation. The dynamic critical stress intensity factor (KICd$K_{IC}^d$) is extracted...

The Kolsky (or split-Hopkinson) bar has been the primary experimental method for obtaining high rate material behavior since the late 1940s. It is a diverse experimental device that allows for the study of material response ranging from brittle to ductile, and even hyperelastic behavior. At the same time, extracting the response of low-impedance ma...

Lissajous figures are parametric equations that deconstruct into equations of simple harmonic motion. They were a source of inspiration by artists and mathematicians alike, well before the digital age, due to their esthetic forms and simple equations that could be easily deconstructed. Here for the first time in literature, we present Lissajous pat...

The role of microstructure and strain rate on the development of geometrically necessary dislocation (GND) density in polycrystalline copper subjected to compression is assessed via crystal plasticity modelling and electron microscopy. Micropolar crystal plasticity finite element (MP-CPFE) simulations show that GND density is strongly dependent on...

Structures used in naval applications are often subjected to marine or other aqueous environments during their work-life. It has been observed that many composites absorb moisture when exposed to such environments, which can lead to material damage and degradation of mechanical properties. The addition of salt to the water solution may have additio...

This study explores the role of rubber toughening on the dynamic fracture behavior of additively manufactured (AM) high-performance thermosetting polymers formed through digital light processing (DLP). Using DLP to create these polymers allows for rapid, agile manufacturing of prototypes meeting the lightweight and building speed requirements of re...

Polymer matrix composites often exhibit a strong strain rate dependance in their mechanical response. In many of these materials, the viscoelastic behavior of the polymer matrix drives the rate dependence in the composite, however identifying these parameters at high strain rate presents a significant challenge. Common high-rate material characteri...

Recently, we have established that, when loaded in compression, edge-on, atomic layers in layered solid can fail by buckling. The resulting structure is termed a ripplocation. When more than one layer buckles, they outline standing waves with boundaries that we labeled ripplocation boundaries that are nearly fully recoverable. In this paper, we exa...

In this study, coupon specimens of both poled and de-poled lead zirconate titanate (PZT) are examined under quasi-static and stress-wave loading conditions. Mode-I crack initiation and fracture behavior is examined using ultra high-speed imaging in conjunction with 2D digital image correlation on symmetrically impacted specimens. Measured displacem...

The MAX phases comprise of a group of layered ternary carbides that exhibit unique mechanical properties which bridge the gap between their metal and ceramic constituents. To study the effects of the global grain orientation, Ti, Si and TiC powders were hot pressed to synthesize highly oriented bulk Ti3SiC2. X-ray diffraction (XRD) was used to veri...

Dynamic Behavior of Materials, Volume 1 of the Proceedings of the 2020 SEM Annual Conference & Exposition on Experimental and Applied Mechanics, the first volume of seven from the Conference, brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and a...

High entropy alloys (HEAs) have been the subject of significant research in recent years due in part to their excellent mechanical properties and unique microstructure. Chemical disorder in these alloys is thought to lead to a complex energetic environment that affects the nucleation and movement of dislocations. In this study the development of de...

Dynamic Behavior of Materials, Volume 1 of the Proceedings of the 2019 SEM Annual Conference & Exposition on Experimental and Applied Mechanics, the first volume of six from the Conference, brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and app...

The purpose of this study is to quantitatively characterize the compressive and damage behavior of a woven fiberglass composite under combined environmental loading. Cuboidal samples of a commercially available woven fiberglass epoxy resin composite, garolite G10, are examined under uniaxial compressive loading perpendicular to the plies at quasi-s...

This paper presents a novel, tunable impact fatigue device that can be configured to apply compressive strikes on a variety of materials and geometries at low to intermediate strain rates, and the ability to compliment the investigations using full-field quantitative visualization of material deformation and failure properties. The device ranges in...

This study explored experiential learning opportunities for undergraduate students in the area of energy and environment as part of a National Science Foundation (NSF) funded Research Experience for Undergraduate students (xREU). This summer research project was conducted in a private university located in the northeastern United States. Since the...

This study explored experiential learning opportunities for undergraduate students in the area of energy and environment as part of a National Science Foundation (NSF) funded Research Experience for Undergraduate students (xREU). This summer research project was conducted in a private university located in the northeastern United States. Since the...

Application of Forward Modelling and Dictionary Indexing to EBSD Orientation Data as a Means of Quantifying Dislocation Substructure Formation in FCC Metals - Volume 25 Supplement - Daniel L. Foley, Cassandra Pate, Kyle Matthews, Xingyuan Zhao, Nicolas Savino, Marc DeGraef, Leslie Lamberson, Mitra L. Taheri

This paper explores the fracture behavior of niobium carbides of varying compositions between NbC1.0 and NbC0.5. The surface crack in flexure (SCF) method was used to evaluate the fracture toughness as a function of carbon concentration. Additionally, hardness measurements were conducted with a Knoop indenter, and X-ray diffraction (XRD) and scanni...

Polymeric foams are used for impact protection due to their ability to absorb large amounts of strain energy. In this work, the compressive response of an open cell polyurethane foam currently used as liner in the advanced combat helmet is examined across strain rates. A traditional load frame is used to investigate the quasi-static behavior, and t...

Layered solids are ubiquitous in nature: from subnanometer graphene and mica layers, to wood, laminated composites, and paperboard at the centimeter scale, to geologic formations at the kilometer range. And while the similarities between the latter two have been recognized [Budd et al., Philos. Trans. R. Soc. A 370, 1723 (2012)], what has not is th...

Dynamic Behavior of Materials, Volume 1 of the Proceedings of the 2018 SEM Annual Conference & Exposition on Experimental and Applied Mechanics, the first volume of eight from the Conference, brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and a...

p>In order to model the dynamic failure of engineering structures it is necessary to have a thorough understanding of dynamic fracture processes. Dynamic fracture toughness has been experimentally analysed by fitting the K-dominant solution to the displacement field measured with a local or full-field technique, such as caustics, photoelasticity or...

Digital image correlation (DIC) is a non-contact, optical, full-field displacement measurement technique used to map deformations on a body under an applied load by tracking surface features. It is a widely used method in experimental mechanics, owed in part to its ease of setup, and applicability across length scales and material systems. Most com...

With more than 1 trillion artificial objects smaller than 1 μm in low and geostationary Earth orbit, space assets are subject to the constant threat of space debris impact. These collisions occur at hypervelocity or speeds greater than 3 km/s. In order to characterize material behavior under this extreme event as well as study next-generation mater...

Tungsten carbide has both industrial and military applications, from high strength end mill dies and geological drilling, to kinetic energy penetrators. In these extreme environments, an understanding of the dynamic fracture properties and the potential influence of grade microstructure is necessary. The present work investigates fracture behavior...

A hybrid experimental-computational method is presented which takes full-field displacement data from DIC and evaluates dynamic stress intensity factors (SIFs) at fracture initiation and propagation. The technique relies on the principles of linear elastic fracture mechanics, and as such the input data must maintain a region of K-dominance ahead of...

Electrical response from dynamic compression tests on x-cut single crystal α-quartz specimens at strain rates of 10(E)3 1/s reveal nonsimilar stress-charge behavior during damage evolution. Specifically, when quartz is undergoing extensive and irreversible dynamic brittle fracture under a compressive stress impulse of up to 1.8 GPa, the effective p...

Dynamic Behavior of Materials, Volume 1 of the Proceedings of the 2016 SEM Annual Conference& Exposition on Experimental and Applied Mechanics, the first volume of ten from the Conference, brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and appl...

Due to their layered structure, MAX phase ternary carbides and nitrides exhibit unique mechanical properties between their metal and ceramic constituent materials. Pre-cracked coupons of MAX phase Ti3SiC2 were impacted at 4 m/s, and high-speed imaging combined with digital image correlation (DIC) captured full-field displacement data during loading...

The rate-dependent compressive response and resulting fragmentation characteristics of dry ox cortical bone and cyanoacrylate-based cortical bone surrogate material was investigated in two material orientations. Tests were conducted under quasi-static (10−3 s−1) and dynamic (103 s−1) loading in the longitudinal and transverse direction with respect...

Dynamic Behavior of Materials, Volume 1 of the Proceedings of the 2015SEM Annual Conference& Exposition on Experimental and Applied Mechanics, the first volume of nine from the Conference, brings together contributions to this important area of research and engineering. The collection presents early findings and case studies on fundamental and appl...

Two types of high performance fiberglass panels were investigated at normal impact conditions of around 1 km/s (2200 mph). Thin phenolic laminates of plain-weave glass cloth impregnated with synthetic thermosetting resins, one melamine and the other epoxy, were impacted by a 1.6 mm diameter nylon sphere using a combustionless two-stage light-gas gu...

Woven composites can offer mechanical improvements over more traditional engineering materials, yet understanding the complex interplay between the fiber-matrix architecture during loading remains a challenge. This paper investigates the evolution of shear failure behavior during the compression of high performance fiberglass composites with varyin...

An accurate understanding of fracture in human bone under complex loading scenarios is critical to predicting fracture risk. Cortical bone, or dense compact bone, is subject to complex loading due to the inherent multi-axial loading conditions, which are also influenced by the anisotropy of the microstruc-ture. When determining critical fracture pa...

Ceramic materials are used extensively in armor applications for both solider and vehicle protection. Certain ceramics, such as silicon carbide, exhibit piezoelectricity, however the coupling between mechanical and electrical fields is not currently utilized. This paper highlights a unique experimental methodology mat measures the in-situ electrome...

A simple perforation prediction model which describes the size of the hole created in a thin metallic plate is presented and compared to hypervelocity impact experiments. The new mechanics model is based on the 1959 Charters model, but takes into account the initial compressive wave on impact by replacing the characteristic deformation stress with...

Two independent optical methods are used to analyze the dynamic material behavior of Mylar and Homalite-100 subjected to hypervelocity impact. Birefringent targets are loaded in tension inside a two-stage light-gas gun vacuum chamber, and are impacted with a 5 mg nylon slug at velocities between 3 and 6 km/s. Caustics and photoelasticity combined w...

One of the prominent threats in the endeavor to develop next-generation space assets is the risk of space debris impact in earth’s orbit and micrometeoroid impact damage in near-earth orbit and deep space. To date, there is no study available which concentrates on the analysis of dynamic crack growth from hypervelocity impacts on such structures, r...

Two independent optical methods are used to analyze the dynamic material behavior of Mylar and Homalite-100 subjected to hypervelocity impact. Birefringent targets are loaded in tension inside a two-stage light-gas gun vacuum chamber, and are impacted with a 5 mg nylon slug at velocities between 3 and 6 km/s. Caustics and photoelasticity combined w...

Hypervelocity impact is a rising concern in spacecraft missions where man-made debris in low-earth orbit as well as micrometeroids have the potential to damage not only the structural components, but also the optical, electrical, and thermal components of a space asset. Little has been investigated regarding damage mechanisms and dynamic fracture m...

Hypervelocity impact is a rising concern in spacecraft missions where man-made debris in low-earth orbit as well as micrometeroids have the potential to damage not only the structural components, but also the optical, electrical, and thermal components of a space asset. Little has been investigated regarding damage mechanisms and dynamic fracture m...

Hypervelocity impact is a high-energy-density phenomenon that has the potential to alter a spacecraft or orbiting asset trajectory, as well as structural, thermal, optical, and electrical properties. The most challenging aspect of hypervelocity impact analysis is the fact that a universal theory does not exist to fully describe this complex phenome...

The extracellular layers of the sea urchin egg are used as a model system for understanding the role of stochastically-placed fibers in providing reinforcement. We present preliminary results of deformation of the egg, and, at a smaller scale, some results on percolation modeling of fibrous materials to determine percolation points in closed-form....