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Natural fibres like banana and jute are recyclable and biodegradable. The effective utilization of the natural fibre in various applications is gradually increasing due to their environment friendliness. The present work focusses on the dimensional and mechanical properties of banana and jute-blended needle-punched nonwoven fabrics. The needle-punched nonwoven fabrics have been produced with 100% banana, 100% jute and in various blend proportions of banana/jute; 80/20, 60/40 and 40/60, respectively. The dimensional, mechanical properties and pore size of the needle-punched fabrics were tested. The needle-punched fabrics produced with 100% banana and 80/20 banana/jute shows lower air permeability, higher bursting strength and better puncture resistance. The 100% banana fabric also shows lower pore size structure which makes it suitable for geo-textile and agriculture textile applications, where the properties like biodegradability and minimum mechanical strength are critical.

Nanotechnology is an evolving technology, resulting in significant differences in product behavior. Applications of Nano materials in textiles are constantly growing to improve performance and create unparalleled textile functions for their enormous technical, economic and ecological advantages. It is expected that Nano materials will either enhance existing properties or add new functionalities to textiles such as dirt and water repellent, breathability, UV protection, conductive and anti-static properties, wear and wrinkle resistance or stain resistance or bacteria. Due to advancement in manufacturing of Nano materials, a new developed materials specified in the area of protection has been discovered such as; carbon Nano tube (CNT) and Graphene. CNT has unique mechanical properties, particularly in improving tensile strength, and is one of the strongest known materials used in high-performance nanocomposites due to their unique mechanical properties. And its properties make it the best to reinforce polymers and have a great potential for use in the manufacture of ballistic-resistant materials. Graphene is an allotrope of carbon that exists as a two dimensional sheet. graphene is as a single layer of graphite, where all the carbons exist in a regular hexagonal array, it’s the first two dimensional materials to be available. It is both the lightest known substance and the strongest ever produced. The ability to be solid, strong and flexible at the same time gives this incredible potential for use as a body armor or shielding. Research Subject: Insufficiency of puncture resistant Nano treated fabrics in the Egypt. Objective: Develop and improve puncture resistant factor for cotton fabrics using Nano technology in Egypt. Methodology: Experimental method. Results: The most important results are Emphasize the effective role of Nano technology in puncture resistant in textiles. Through Nano technology and Nano additives a wide range of properties could be added to fabrics. The impact proof treatments of fabrics and material developments have several applications. The mechanical properties of textile fibers can be enhanced by incorporation of nanoparticles in fiber, such properties include increasing puncture resistant. Hematite (Iron III Oxide) Nanoparticles were applied to cotton fabrics using polyurethane cold cure foams as a binder, the treatment enhanced the mechanical properties ‘puncture resistant’, The experiment shows a significant increase in puncture resistance for treated fabrics. Effect of Nano iron on physical properties of cotton fabric lead to Changes in physical properties of Nano iron loaded cotton fabric was evaluated in terms of puncture resistance and compared with the untreated cotton fabric.

Protective textiles require massive consumption of fibers and fabrics, which is responsible for diverse highstrength fabric waste. Wrongly arranged disposal of textile waste is equivalent to the waste valuable resource while causing environmental pollutions. Aramid selvages are worthwhile recycling and used in this study. They are scattered into Aramid staple fibers and mixed with low melting point polyester (LMPET) fibers to form the Aramid matrices employing the nonwoven process. The matrices are added to different combinations to form Aramid composite matrices and hybrid-fiberreinforced composite boards. The process of shearing, crowding, and friction helps improve the mechanical properties of the composite boards according to the evaluations of conducted tests. With the premise of minimum damage to the fibers, this study uses recycled Aramid waste to produce composite boards that have features of high performance and low production cost. As a test result, the hybrid-fiber-reinforced composite boards with 90 wt% of recycled Aramid fibers have the optimal mechanical property and static puncture resistance.

The ballistic impact mechanism mainly depends on the thickness , dimension , strength , ductility , toughness , and density of the target material. Nanotechnology is an evolving technology, resulting in significant differences in product behavior. Nanomaterials are increasingly used in textiles to increase performance and provide unrivaled textile functionality. It is anticipated that materials such as dirt and waterproofing, breathability , UV protection, conductivity, and antistatic qualities, wear and wrinkle resistance, and stain resistance, and bacteria will be enhanced by nanomaterials or add new features. By incorporating nanoparticles into fibers, the mechanical qualities of textile fibers can be strengthened.

Auxetic materials expand in at least one dimension, when stretched longitudinally i.e. they have negative Poisson’s ratio. Development of 2D woven auxetic fabrics (AF) is a new approach to develop mechanically stable auxetic textile structures. However, the mechanical response of such emerging structure is still not studied in detail yet, therefore different mechanical properties of 2D woven AF are compared with conventional non-auxetic fabric (NAF). AF was developed by orienting yarns in auxetic honey-comb (AHC) geometry and auxeticity is induced due to such orientation of yarns. AF was developed using conventional (non-auxetic) materials; cotton yarn and elastane cotton yarn in warp and weft dimension respectively, using air jet loom. Structure and auxeticity of AF were analyzed using a digital microscope and its different mechanical properties (tensile strength, tear strength, bursting strength, cut resistance, and puncture resistance) were studied. AF showed superior mechanical properties with a lower initial modulus, which is beneficial for different protective textiles applications like cut resistance gloves, blast resistant curtains, and puncture tolerant elastomeric composites.

For structures that carry dynamic loads, the requirements are imposed for safety reasons. The requirements apply to both materials and construction. This requires searching for optimal calculation methods, including geometric and physical nonlinearity, which are results from the construction of the structure. An example is various ballistic structures (ballistic shields), which are hit by bullets in which huge energy is accumulated. In this case, the hitting in the shield with a bullet can be considered as a load due to mass impact. Loads at high strain rates are described by various mathematical models. The mathematical model is complex because a large number of "coefficients" is required, moreover, the obtained test results are not always repeatable. The paper presents the results of shooting multilayer plates with composite materials with 7.62 mm caliber bullets. The shield consisted of three layers, the outer layers were steel or aluminum, the inner layer was natural or modified wood. The samples had the shape of a shield and were 50 mm in diameter and of different thickness. The results of the research allowed to assess the impact of wood modification on its puncture resistance.

Flexible natural armors from fish, alligators or armadillo are attracting an increasing amount of attention for their unique combinations of hardness, flexibility and light weight. The extreme contrast of stiffness between hard scales and surrounding soft tissues gives rise to unusual and attractive mechanisms, which now serve as models for the design of bio-inspired armors. Despite this growing interest, there is little guideline for the choice of materials, optimum thickness, size, shape and arrangement for the protective scales. In this work, we explore how the geometry and arrangement of hard scales can be tailored to promote scale-scale interactions. We use 3D printing to fabricate arrays of scales with increasingly complex geometries and arrangements, from simple squares with no overlap to complex ganoid-scales with overlaps and interlocking features. We performed puncture tests and flexural tests on each of the 3D printed materials, and we report the puncture resistance – compliance characteristics of each design on an Ashby chart. The interactions between the scales can significantly increase the resistance to puncture, and these interactions can be maximized by tuning the geometry and arrangement of the scales. Interestingly, the designs that offer the best combinations of puncture resistance and flexural compliance are similar to the geometry and arrangement of natural teleost and ganoid scales, which suggests that natural evolution has shaped these systems to maximize flexible protection. This study yields new insights into the mechanisms of natural dermal armor, and also suggests new designs for personal protective systems. Statement of Significance Flexible natural armors from fishes, alligators or armadillos are attracting an increasing amount of attention for their unique and attractive combinations of hardness, flexibility and low weight. Despite a growing interest in bio-inspired flexible protection, there is still little guideline for the choice of materials, optimum thickness, size, shape and arrangement of the protective scales. In this work, we explore how the geometry and arrangement of hard scales affect puncture resistance and flexural compliance, using 3D printing and mechanical testing. Our main finding is that the performance of the scaled skin in terms of puncture resistance can be significantly improved by slight changes in their geometry and arrangement. Our results also suggest that natural evolution has shaped scaled skins to maximize flexible protection. This study yields new insights into the mechanics of natural dermal armors, and also suggests new designs for personal protective systems.

Polyurethane is a polymer adaptable to different scientific and industrial requirements, nevertheless it is also extremely susceptible to UV radiation, which compromises the physical and mechanical functionality. In this framework, our study investigated the effect of waterborne polyurethane dispersion (WPUD) applied to a polyester (PET)-based fabric, through the impregnation method, on the puncturing and water resistance of the pristine material, before and after UV weathering. Results confirmed an increment of both features in the prepared fabrics, attributed to the PUR textile treatment, but a partially loss of the gained properties in the samples due to the UV weathering. In order to improve the efficiency of the impregnating dispersions, in protecting the durability of the treated materials, the addition of different UV light stabilizers, or/and of crosslinking agent into WPUD was also tested. From the experimental data, it can be concluded that formulations based on WPUD, containing both the crosslinker and UV organic absorber, have displayed an increment of their perforation and water resistance for the treated samples with respect to the starting textile, and contemporary have preserved the features against the UV light. Finally, microscopic and spectroscopic analyses have been performed as further characterization techniques of the samples surface.

Geotextiles are commonly used in pavements, earth retaining structures, and landfills, as well as in other geotechnical applications. The puncture strength test evaluates the ability of geotextiles to withstand stresses and loads during construction, which are among the severe conditions that geotextiles can experience. ASTM has recently replaced the standard pin puncture strength test, D4833, with the California bearing ratio (CBR) puncture strength test, D6241. However, many state departments of transportation and the FHWA still refer to ASTM D4833. Other state departments of transportation refer to ASTM D4833 and to D6241 or provide a list of alternative test methods to be considered in place of either of these tests. The objective of this research was to correlate the CBR and pin puncture strengths for various categories of geotextiles, regardless of weave type and mass per unit area. Five types of polypropylene geotextiles, three nonwoven and two woven, were subjected to testing in accordance with ASTM D4833 and D6241 standard procedures. Ten and 15 samples of each geotextile type were tested with CBR and pin puncture strength tests, respectively. All five types of geotextiles exhibited puncture strength values, whether pin or CBR, which were consistent within each group. Similarly, distinct load-displacement curves were exhibited within each material group. Statistical analyses were conducted to establish a correlation between the CBR and pin puncture strength values. The correlations were successfully used to estimate the CBR puncture strength values from the pin test with reasonable accuracy ( R2 = .78).

The low-earth orbit environment contains small micrometeoroid and orbital debris (MMOD) particles traveling at characteristic velocities of several kilometers per second. In addition to being a direct threat to astronauts and spacecraft, upon impact with the exterior surface of a space vehicle, these highly energetic MMOD particles can create cut and puncture hazards for astronauts performing extra-vehicular activities (EVA). In this work, we demonstrate that replacing the standard neoprene-coated nylon absorber layers with woven aramid textiles intercalated with colloidal shear thickening fluids, i.e., STF-Armor™, can provide a meaningful enhancement to the cut and puncture resistance of the thermal micrometeoroid garment (TMG). Quasi-static puncture testing is performed using hypodermic needles of varying gauge to simulate the cutting and puncture hazards at deformation rates characteristic of human motion. At equal areal densities, we find that a TMG lay-up containing STF-Armor™ greatly improves puncture protection with a reduction in weight and comparable flexibility.

This paper presents a computational framework that analyzes the effect of fluid–structure interaction (FSI) on the impact dynamics and puncture failure of pressurized commodity tank cars carrying hazardous materials. Shell (side) impact tests have been conducted on full scale tank cars resulting in deformed or punctured tank cars. A finite element (FE) modeling method is applied that explicitly simulates the three distinct phases in a tank car loaded with a liquefied substance: pressurized gas, pressurized liquid and solid structure. Furthermore, an equivalent plastic strain based fracture initiation criterion expressed as a function of stress triaxiality is adopted to depict the fracture behavior of the tank car steel material. The fracture initiation is implemented for ductile, shear and mixed fracture modes and followed by further material deterioration governed by a strain softening law. The force, displacement and impact energy results obtained from the FE analysis show good agreement with the corresponding shell impact test data. The simulations demonstrate that FSI plays a critical role in predicting the correct dynamics of tank car impact. The puncture resistance of a tank car, characterized as limit impact conditions in terms of puncture energy or puncture velocity, is further analyzed in shell impact scenarios. The puncture energy is shown to increase as the initial fluid pressure decreases, the tank car thickness increases or the effective impactor size increases. Quantitative correlations between puncture energy/velocity and each of these factors are obtained using the FE analysis method developed in this paper.

The U.S. Department of Transportation’s Federal Railroad Administration (FRA) has sponsored a series of full-scale dynamic shell impact tests to railroad tank cars. Currently, there are no required finite element (FE) model validation criteria or procedures in the field of railroad tank car puncture testing and simulation. Within the shell impact testing program sponsored by FRA, comparisons made between test measurements and simulation results have included the overall force-time or force-indentation histories, the puncture/non-puncture outcomes, the rigid body motions of the tank car, the internal pressures within the lading, and the energy absorbed by the tank during the impact. While qualitative comparisons (e.g. the shapes of the indentation) and quantitative comparisons (e.g. peak impact forces) have been made between tests and simulations, there are currently no requirements or guidelines on which specific behaviors should be compared, or what measurable level of agreement would be acceptable demonstration of model validation. It is desirable that a framework for model validation, including well-defined criteria for comparison, be developed or adopted if simulation is to be used without companion shell impact testing for future tank car development. One of the challenges to developing model validation criteria and procedures for tank car shell puncture is the number of complex behaviors encountered in this problem, and the variety of approaches that could be used in simulating these behaviors. The FE models used to simulate tank car shell impacts include several complex behaviors, each of which can introduce uncertainty into the overall response of the model. These behaviors include dynamic impacts, non-linear steel material behavior, including ductile tearing, two-phase (water and air) fluid-structure interaction, and contact between rigid and deformable bodies. Several candidate qualitative and quantitative comparisons of test measurements and simulations results are discussed in this paper. They are applied to two recently-completed shell impact tests of railroad tank cars sponsored by FRA. For each test, companion FE simulation was performed by the Volpe National Transportation Systems Center. The process of FE model development, including material characterization, is discussed in detail for each FE model. For each test, the test objectives, procedures, and key instrumentation are summarized. For each set of test and simulations, several corresponding results are compared between the test measurements and the simulation results. Additionally, this paper includes discussion of approaches to model validation employed in other industries or areas of transportation where similar modeling aspects have been encountered.

This study purposes to investigate acoustic absorbing and puncture resisting properties of wall covering composites with different number of layers, and then to construct prediction model of acoustic absorption coefficient. Puncture resistance linearly increases but maximum absorption coefficient shifts to lower frequency with number of layers.The acoustic absorbing property of wall covering composites presents porous acoustic-absorbing characteristic, and its prediction model correlates with critical frequency and maximum absorption coefficient. The resulting coverings have excellent puncture resistance and acoustic absorbing properties.

Thanks to its excellentprotective properties, lightness, a reasonable price, and ecology, corrugated paperboardis one of the most popular materials used in the production of packaging for variousproducts. During transportation or storage, packaging with goods can be exposedto the mass of other commodities, dropping from heights and transportationshock loads, which can lead to their puncture damage. Depending on the purposeand size of the packaging, the thickness, grammage, constituent paper layers,numbers of layers and type of fluting of corrugated paperboard used in itsproduction differ. A standard triangular prism, corrugated paperboard fixationplates and a universal tension-compression machine were used to investigate theimpact of corrugated paperboard structure and other parameters on the punctureresistance of the material. The investigation determines the maximum punctureload and estimates energy required to penetrate the corrugated paperboard. Itwas found that the greatest puncture resistance is demonstrated by paperboardwith a larger number of corrugating flutings and the board produced from harderpaper with a smaller amount of recycled paper. It was established that thegrammage of three-layered paperboard with two different fluting profiles has thegreatest impact on the level of static puncture energy.DOI: http://dx.doi.org/10.5755/j01.ms.21.1.5713

This study prepared inter/intra-ply hybrid composites reinforced with sandwich-structure recycled Kevlar nonwoven/glass woven compound fabric. Negative-depth needle punching and thermal bonding were applied to strengthen the structure with two compound cover plies and a fluffy cushioning center ply. The effects of center ply areal density, needle punching depth, and fiber blending ratio on the static and dynamic impact resistance behaviors of the composites were investigated. The results indicated that areal density significantly influenced the static and dynamic impact behaviors, which were both enhanced by the promotion of thermal-bonding points. As the needle punching deepened, the static and dynamic puncture resistances represented opposite tendencies because of different failure mechanisms. Static friction was the dominant factor for static puncture resistance, whereas kinetic friction was the dominant factor for dynamic puncture resistance. A similar phenomenon was observed when fiber blending ratio was varied. In terms of the non-penetrating dynamic cushioning test, areal density was the most distinct influence factor on cushioning behavior and the hybrid composites sample with an areal density of 700 g/m 2 could eliminate up to 66.5% of the incident force. Therefore, the inter/intra-ply hybrid composites showed high impact resistance and excellent dynamic cushioning property.

Absorber layers comprised of shear thickening fluid (STF) intercalated Kevlar® (STF-ArmorTM) are integrated within the standard extra-vehicular activity (EVA) suit and tested for efficacy against both needle puncture and hypervelocity impact (HVI) tests characteristic of micrometeoroids and orbital debris (MMOD). An improvement in puncture resistance against hypodermic needle threats is achieved by substituting STF-ArmorTM in place of neoprene-coated nylon as the absorber layer in the standard EVA suit. The prototype lay-ups containing STF-ArmorTM have the benefit of being 17% thinner and 13% lighter than the standard EVA suit and the ballistic limit is identified in HVI testing. The results here demonstrate that EVA suit lay-ups containing STF-ArmorTM as absorber layers offer meaningful resistance to MMOD threats.

The Federal Railroad Administration’s Office of Research and Development is conducting research into passenger locomotive fuel tank crashworthiness. A series of impact tests is being conducted to measure fuel tank deformation under two types of dynamic loading conditions — blunt and raking impacts. The results of this research program assist in development of appropriate standards for puncture resistance requirements to be applied to alternatively-designed fuel tanks, such as on diesel multiple unit (DMU) passenger rail equipment. This paper describes the results of the first blunt impact test performed on a DMU fuel tank. On June 28, 2016, FRA performed a dynamic impact test of a fuel tank from a DMU rail vehicle. The test was performed at the Transportation Technology Center (TTC) in Pueblo, Colorado. An impact vehicle weighing approximately 14,000 pounds and equipped with a 12-inch by 12-inch impactor head struck the bottom surface of a DMU fuel tank mounted vertically on an impact wall. The impact occurred on the bottom of the fuel tank at a location centered on two baffles within the fuel tank. The target impact speed was 11.5 mph, and the measured impact speed 11.1 mph. The test resulted in a maximum indentation of approximately 8 inches, the bottom of the tank bending away from the wall, and buckling of several internal baffles. Following the test, the tank was cut open to inspect the damage to the internal structure. This revealed that the buckling behavior of the baffles was isolated to the baffles immediately adjacent the impact location, each one buckling as the tank deformed inward. Prior to the test, finite element analysis (FEA) was used to predict the behavior of the tank during the test. The FE model of the tank required material properties to be defined in order to capture plastic deformation. The combination of metal plasticity, ductile failure, and element removal would permit the model to simulate puncture for this tank at sufficiently-high impact speeds. The pre-test FE model results compared very favorably with the test measurements, and both the pre-test model and the test resulted in similar modes of deformation to the DMU fuel tank. Following the test, material coupons were cut from undamaged areas of the fuel tank and subjected to tensile testing. The post-test FE model was updated with the material behaviors from the post-test material testing. This test is part of a research program investigating puncture resistance of passenger locomotive fuel tanks. The objective of this research program is to establish the baseline puncture resistance of current locomotive fuel tanks under dynamic impact conditions and to develop performance requirements for an appropriate level of puncture resistance in alternative fuel tank designs, such as DMU fuel tanks. Future tests are planned within this research program. The lessons learned during the series of tests support finite element (FE) modeling of impact conditions beyond what was tested. Additional tests investigating the puncture resistance of fuel tanks during sideswipe or raking collisions are also planned.

In order to realize recycling of polypropylene selvages, polypropylene nonwoven selvages with different plied orientation were inserted between Kevlar/Nylon/low-melting polyester nonwoven fabrics forming composite nonwoven. Low-melting polyester content of nonwoven fabric and hot-pressing temperature of composite nonwoven were both optimized after static and dynamic puncture resistances. Moreover, effects of hot-pressing and plied orientation on static and dynamic puncture resistances, sound absorbing and thermal insulating properties of composite nonwoven were discussed respectively. Result shows that, optimal low-melting polyester fiber content was 30%, and best hot-pressing temperature for composite nonwoven was 180°C. Polypropylene nonwoven selvages improved static puncture resistance, sound absorbing and thermal insulating properties. Hot-pressing slightly increased puncture resistance and obviously improved thermal insulation, but decreased sound absorption coefficient significantly. Plied orientation affected static and dynamic puncture resistance insignificantly, but influenced on sound-absorbing and thermal-insulating properties significantly. When composite nonwoven was plied with 90°/90° polypropylene selvages and hot-pressed at 180°C, the static and dynamic puncture resistances reached 120 N and 80 N, respectively, and thermal conductivity was 0.047 W/mK. Five layers of composite nonwoven before hot-pressing had sound absorption coefficient of above 0.94 at frequency of higher than 1890 Hz.

The paper presents the puncture resistance of the material, that is under the influence of highly deformable projectile, depending on changes of material’s yield strength. The simulation has been conducted using mobile cellular automata (MCA) with authors’ own software. The simulation took into account the elasto-plasto-viscous properties of the material as well as surface and internal friction. The selected results are illustrated in terms of piercing the multilayer material with chosen projectiles of kinetic influence in the range of impact velocity between 300 and 1000 m/s.

This paper reveals the manufacturing process and static impact resistance of sandwich structural hybrid laminates composed of high-resilience bonding polyester /Kevlar intra-ply hybrid nonwovens and E-glass woven fabric. The effects of various weight ratio of Kevlar fiber on the mechanical behaviors, including tensile strength, tear strength, bursting strength and puncture strength, were evaluated. The experimental results indicated that the tensile strength and fracture work were both enhanced with the increase in Kevlar content. The tear strength on CD and MD exhibited opposite trends when varying the Kevlar content. The static bursting and puncture resistances were both enhanced with the promotion of Kevlar content. The failure mechanisms of the breakages were also analyzed.

The most common case of conveyor belts damage is their puncture by falling sharp material. One of the ways, how to minimize this type of damage, is using of suitable type of conveyor belt. Therefore, the analysis of conveyor belts on the part of their puncture resistance is an important factor for their use in operation conditions. The aim of the paper is to determine the dependence among the weight of sharp material falling on the conveyor belt, shatter height and force conditions in the conveyor belt on the base of experimental measurements by the help of regression mathematical model and to determine conditions under which the conveyor belt is damaged. The experimental results enable the operator of a conveyor belt to set the shatter height and maximum weight of falling weight below the threshold values in order to prevent conveyor belt damage.

As improvement of industry and society, some potential crisis happened in working and living environment is taken into account by human people. Meanwhile, different kinds of protective appliances develop rapidly, and composite boards with cushion and puncture-resistance property are required consequently. This study aims to develop a cushion/puncture-resistance PU foam protective composites. This paper used Polyol and Isocyanate to prepare porous PU foam composite via foaming and curing process. By changing foam density and addition amount, cushion and puncture-resistance property were tested and then evaluated to seek for PU foam composite with cushion and puncture-resistance property. Result shows that, when density was 80 kg/m3, PU foaming composite board had the optimum resilience rate of 44 %, lowest impact remaining load of 638 N and best puncture-resistance force of 138.3 N.

The dynamic puncture resistance of multi-layer integrated composite which was comprised of glass fabric reinforcement or Kevlar fabric reinforcement and nonwovens were discussed as related to recycled Kevlar fibers amount, number of layer and K-ply position for purpose of cost reduction and performance improvement. The result shows that, 20 wt% Kevlar fibers contained in nonwovens have the optimum puncture resistance. And the dynamic puncture force increases linearly with number of layers, and also improves proportionally as increasing number of K-ply. The resultant multi-layer composite is expected to be used as body armor interlayer and packaging materials.

The structural integrity of the package is critical for protecting the product from packing through distribution and use. In multilayer flexible packaging, often one or more layers are specifically incorporated to bear the load when it comes to strength and integrity, but the other layers play a role as well. This chapter looks at various aspects of structural integrity, including tensile strength; flexural stiffness; and tear, scratch, puncture, and impact resistance. The importance of these attributes, how they are measured, and how they are impacted by the design of the multilayer film are explored.

This paper is the second in a two-part series on the puncture performance of railroad tank cars carrying hazardous materials in the event of an accident. Various metrics are often mentioned in the open literature to characterize the structural performance of tank cars under accident loading conditions. One of the consequences in terms of structural damage to the tank during accidents is puncture. This two-part series of papers focuses on four metrics to quantify the performance of tank cars against the threat of puncture: (1) speed, (2) force, (3) energy, and (4) conditional probability of release. In Part I, generalized tank car impact scenarios were illustrated. Particular focus is given to the generalized shell impact scenario because performance-based requirements for shell puncture resistance are being considered by the regulatory agencies in United States and Canada. Definitions for the four performance metrics were given. Physical and mathematical relationships among these metrics were outlined. Strengths and limitations of these performance metrics were discussed. In this paper (Part II), the multi-disciplinary approach to develop engineering tools to estimate the performance metrics is described. The complementary connection between testing and modeling is emphasized. Puncture performance metrics, which were estimated from other sources, are compared for different tank car designs. These comparisons are presented to interpret the metrics from a probabilistic point of view. In addition, sensitivity of the metrics to the operational and design factors is examined qualitatively.

This paper is the first in a two-part series on the puncture performance of railroad tank cars carrying hazardous materials in the event of an accident. Various metrics are often mentioned in the open literature to characterize the structural performance of tank cars under accident loading conditions. One of the consequences in terms of structural damage to the tank during accidents is puncture. This two-part series of papers focuses on four metrics to quantify the performance of tank cars against the threat of puncture: (1) speed, (2) force, (3) energy, and (4) conditional probability of release. In this paper (Part I), generalized tank car impact scenarios are illustrated. Particular focus is given to the generalized shell impact scenario because performance-based requirements for shell puncture resistance are being considered by the regulatory agencies in United States and Canada. Definitions for the four performance metrics are given. Physical and mathematical relationships among these metrics are outlined. Strengths and limitations of these performance metrics are discussed. In Part II, the multi-disciplinary approach to develop engineering tools to estimate the performance metrics will be described. The complementary connection between testing and modeling will be emphasized. Puncture performance metrics, which were estimated from other sources, will be compared for different tank car designs. These comparisons will be presented to interpret the metrics from a probabilistic point of view. In addition, sensitivity of the metrics to the operational and design factors will be examined qualitatively.

Mine owners and operators are presented today with a diverse range of geosynthetic products which all appear to provide similar benefits. Key factors in selecting geosynthetics for use in the mining industry include construction and operational durability issues such as slope stability, puncture resistance and resistance to weathering; but also their chemical resistance when they come into contact with the extreme liquors present on many mining operations and processes. The long-term performance of the geosynthetic depends largely on the type of polymer used in the manufacture, or in the case of geosynthetic clay liners (GCLs), also on the mineralogy and chemical make of the bentonite present in the GCL. This paper provides a guide to the characteristics of the leachates/liquors likely to be generated for a given mining process and the likely effect it will have on the performance of a given geosynthetic. 2009 Elsevier Ltd. All rights reserved.

We quantified protection given by a variety of gloves against bat bites by using steel indenters to simulate teeth and measuring forces needed to puncture the gloves. Level of protection given by gloves was compared to expected bite forces and tooth sharpness of bats. Cotton, plastic-coated synthetic fabric, and proprietary materials advertised as puncture- and cut-resistant were easy to penetrate compared to leather gloves. Split leather gives the highest level of protection, but with reduced dexterity. These are best for handling larger bats (>40 g) or if higher safety is preferred. Deerskin gives reasonable protection without much loss in dexterity for handling bats

We introduce a silicone-based vascular prosthesis that may be optimized in various ways. The current work describes the theoretical background, the fabrication process, and the mechanical properties of these new prostheses, allowing objectification and comparison of materials used in vascular surgery. A production process to coat polyester prostheses with silicone-rubber (polydimethylsiloxane, PDMS) was established. Further modifications (surface improvements, drug incorporation for release) can be performed wet-chemically. Measurement of the physical properties included longitudinal and circumferential stability and elasticity, suture retention strength and puncture resistance (tensile testing machine), permeability, and compliance (circulation model). Prostheses can be multiply coated with PDMS. Sufficiently low levels of permeability (5 mL/cm(2)/min at 120 mm Hg) were achieved with a PDMS content15 mg/cm(2). Considering stability, elasticity, and compliance, prostheses with a silicone-rubber content of 15-20 mg/cm(2) are comparable to conventional, primarily tight prostheses. Coating with PDMS decreases suture retention strength and puncture resistance compared to conventional alloplastic materials (collagen-coated polyester and expanded polytetrafluorethylene) materials. The silicone coating surrounds the passing threads ("self-sealing surface") and is resistant to clamping trauma. The complete measurement procedures described here allow for a comparison of new materials with conventional ones and allow the handling characteristics of implants to be objectified. The primarily tight, silicone-coated prostheses can be compared to conventional bovine-coated materials without drawbacks regarding physical properties.

A new type of rubber plug reduces leakage in the Lantus® OptiClick® 300 insulin pen (Sanofi Aventis K.K. ; n-OPC).In order to evaluate this improvement, using a questionnaire, we asked patients whether they had experienced leakage with the pen having the previous rubber plug (o-OPC) as well as concerning the effect of such leakage. Twenty-seven outpatients with diabetes provided responses.In Japan, the pre-filled insulin pen product NovoRapid FlexPen® (Novo Nordisk Pharma K.K. ; FLX) is widely used. As basic testing, we examined the material and structure of its rubber plug, and conducted an insulin injection accuracy test and a puncture resistance test. We also assessed the n-OPC to see how much it prevented the leakage that frequently occurred with the o-OPC. We compared the elasticity of plugs, conducted a puncture resistance test and an accuracy test, and compared how well they fit in the pens.The responses to the questionnaire indicated that leakage increases patient anxiety and required preventive measures to be taken as early as possible. The results of the basic testing showed that there were no problems with the FLX but the o-OPC had problems with regard to all test parameters. For the n-OPC, while the new plug material helped prevent leakage, there were still various points of the product that required improvement.

The Federal Railroad Administration’s Office of Research and Development is conducting research into passenger locomotive fuel tank crashworthiness. A series of impact tests is being conducted to measure fuel tank deformation under two types of dynamic loading conditions — blunt and raking impacts. This program is intended to result in a better understanding of design features that improve the puncture resistance of passenger locomotive fuel tanks. One reason for performing this program is to aid in development of appropriate standards for puncture resistance to be applied to alternatively-designed fuel tanks, such as on diesel multiple unit (DMU) passenger rail equipment. This paper describes the results of the third blunt impact test of retired F-40 locomotive fuel tanks. The test setup was designed for the Transportation Technology Center (TTC) in Pueblo, Colorado, to impart blunt impacts to the bottom of each fuel tank specimen. The specimens tested to date are from FRA-owned retired F-40 passenger locomotives. To conduct the test, each tank was emptied of fluid and mounted on a crash wall with the bottom surface exposed. A rail cart modified with a “rigid” indenter measuring 12 inches by 12 inches, was released to impact the bottom of fuel tank at a target impact speed. The first two tests, conducted on October 8 and 9, 2013, were designed to impact the center of two different tank designs. Tests were conducted at impact speeds of 4.5 and 6.2 mph and caused maximum residual dents of 5 inches and 1.5 inches, respectively. On August 20, 2014 the test of fuel tank 234 was conducted to impact the tank off-center between two baffles. Force-deformation measurements were collected for each tank during the three tests. The series of tests provide information regarding the influence of tank design on puncture resistance. In the test of tank 234, the target impact speed was 12.5 mph, and the actual impact occurred at 11.2 mph. The test resulted in a residual dent depth of approximately 9 inches, and buckling of several internal baffles. The impact did not result in puncture of the tank. Following the test, the tank was cut open to permit examination of the baffles. This examination revealed a different baffle geometry than was modeled based on pre-test measurements. Finite element analysis (FEA) was used to predict the behavior of the tank during the test. The FE model of the tank required several material properties to be defined in order to capture puncture behavior. The combination of metal plasticity, ductile failure, and element removal would permit the model to simulate puncture for this tank. Following the test, the tank was cut open, revealing a different baffle arrangement than had been initially thought. The post-test FE model was then updated to include the actual baffle arrangement of tank 234. With the actual baffle arrangement included in the model, the FE results are in fairly good agreement with the test. Additional changes to the ductile failure criterion were also made in the post-test model. The objective of this research program is to establish the baseline puncture resistance of current passenger locomotive fuel tanks under dynamic impact conditions and to develop performance requirements to ensure an appropriate level of puncture resistance in alternative fuel tank designs, such as DMU fuel tanks.

There has been significant research in recent years to analyze and improve the impact behavior and puncture resistance of railroad tank cars. Ultimately, the results of this work will be used by the Government regulatory agencies in the United States and Canada to establish performance-based testing requirements and to develop methods to evaluate the crashworthiness and structural integrity of different tank car designs. This paper describes results of recent side impact testing and corresponding analyses using detailed finite element analyses (FEA). The test and analyses were performed to evaluate the side impact puncture performance of DOT-111 tank cars. The tank car was filled with water to approximately 97 percent of the volume. The tank was then sealed but not pressurized. The tank car was impacted at the Transportation Technology Center, Inc. by a 297,125-pound ram car with 12-by 12-inch ram head fitted to the ram car impacted the tank center. The analyses were on overall good agreement with the measured impact response. The lading was found to play a more significant role in the impact response than in previous testing and analyses of pressure tank cars. This is not surprising considering the reduced structural stiffness of the tanks compared to thicker pressure tank cars and the reduced effective stiffness from the initially unpressurized tank at impact. The smaller outage volume also contributes to a dramatic increase in the tank pressure as the dent formation reduces the tank volume and compresses the contents of the tank.

The purpose of this work is to describe a numerical procedure that was conducted to examine the effect of internal pressure on the possibility of puncturing and rupturing a high-pressure gas pipeline due to the impact of a falling rock. The mass and the height of the falling object were fixed. The analyses were performed in two parts: first by comparing an initial potential energy of the indenter with the energy needed to dent and possibly puncture the pipeline, then by determining if the resulting puncture would result in unstable crack extension leading to pipeline rupture. Finite element analysis was used to examine various shapes of the indenting surface to assess the effect of contact geometry on the puncture resistance. For cases where puncture is predicted, the dimensions of the hole are compared to the critical pressure to cause rupture, using industry standard methodology. The overall procedure can thus be utilized to determine the critical pressure to avoid a rupture due to a falling rock. By further application of an appropriate safety factor, the safe working pressure for a pipeline excavation can be established.

Double-gloving has been shown to reduce conclusively the risk of operating room personnel's exposure to blood. Limiting risk of exposure to blood by double-gloving provides protection against the transmission of bloodborne diseases. Realizing the importance of double-gloving, a double-glove hole puncture indication system exists that accurately detects the presence of glove hole puncture in the presence of fluid. Once a glove puncture is recognized by this double-glove hole puncture indication system, it provides a warning to the surgeon to remove the punctured gloves, wash hands, and don a new, sterile double-glove hole puncture indication system. While accurately identifying the presence of glove hole puncture in the presence of fluid, this double-glove hole puncture indication system also has resistance to needle puncture superior to that of single gloves. It is the purpose of this study to document the resistance to needle puncture of latex and non-latex double-glove hole puncture indication systems using a reproducible experimental model. The resistance to needle puncture of the double-glove systems was significantly greater than that of the undergloves or outer gloves alone. The resistance to glove puncture of the non-latex and latex single and double-glove systems was significantly greater than those encountered by the latex single and double-glove systems, respectively. On the basis of their accuracy in detecting glove hole puncture, combined with their demonstrated superior resistance to surgical needle puncture as compared to single gloves, these latex and non-latex double-glove hole puncture indication systems are recommended for all surgical procedures.

There has been significant research in recent years to analyze and improve the impact behavior and puncture resistance of railroad tank cars. Ultimately, the results of this work will be used by the Government regulatory agencies in the United States and Canada to establish performance-based testing requirements and to develop methods to evaluate the crashworthiness and structural integrity of different tank car designs. This paper describes analyses of current impact testing requirements and impact test methodologies using detailed finite element analyses (FEA). The results of these analyses are used to identify characteristics of the test methodologies that are desirable or undesirable for the test requirements in future tank car safety regulations.

The purpose of this project is to develop a puncture proof surgical retraction device to aid in surgery, particularly abdominal/thoracic surgery. The client, Dr. Adam D Fox of the division of trauma surgery and critical care at Rutgers University School of Medicine asked for a surgical device to prevent common workplace needle stick injuries that occur during suturing due to the close proximity of assisting surgeon's hands to the suture needle. An additional requirement of the glove is to maintain maximum manual dexterity and increase retraction ability of the assisting surgeon as part of an ideal design. Existing solutions for puncture resistance, increased manual retraction, and sterilization techniques were researched and side-by-side comparisons were used to determine the optimal solution. The proposed reusable design utilizes a puncture-resistant SuperFabric® glove coated in latex with a webbed hand design between the second and fifth digits of the hand. This design best allows for adequate puncture prevention from the four suture needles commonly used in surgery while increasing manual retraction by means of increased surface area. Additionally, material selection and design allows for easily accessible sterilization techniques and conforms to the applicable FDA & OSHA standards for surgical gloves. Extensive testing and research was done to verify the optimal choices of design morphology and the client is overall very pleased with the design. Further testing and evaluation will be completed in the spring semester to verify the validity of the design before final device construction and delivery to the client.

OBJECTIVE: To investigate the puncture resistance of a recently introduced non-latex, nitrile dental glove in comparison with a latex glove worn during routine clinical dental procedures. SETTING: Dentists in general dental practice working within the UK during 1999. SUBJECTS AND METHODS: 2,020 gloves worn by five general dental practitioners were examined for punctures following standard clinical use by a water inflation method. Procedures undertaken during glove usage and length of time worn were recorded. RESULTS: Following clinical use, 1.9% of the latex gloves and 5.3% of the nitrile gloves had punctures, a statistically significant difference (P less than 0.0001). The puncture resistance of the nitrile gloves was superior to the puncture resistance of previously tested worn non-latex (vinyl) gloves. There was no evidence of a statistically significant difference between operators for the percentage or incidence of punctured gloves (P = 0.787) after correcting for glove type. No statistically significant difference was noted between incidence of puncture in the control, unused gloves (n = 200 for each type) and the gloves examined following clinical use (P = 0.907 for nitrile, P = 0.613 for latex). CONCLUSION: No increase in the number of punctures was noted following clinical use for either glove type. This could be considered to indicate good puncture resistance of the gloves tested in clinical use.

This study aims ultimately to quantify the force needed to penetrate human tissue. The results will reduce the subjectivity of expert opinion in stabbing incidents. They will also aid clinicians in assessing the severity of injury and help prevent the unnecessary deaths which can occur when this is not fully appreciated. Tensile tests were performed to identify suitable skin simulants with synthetic chamois and pigskin as candidate materials. Quasi-static penetration experiments were also performed in which a knife blade penetrated a skin simulant target. Pigskin was found to be much stronger than chamois under tensile load yet the puncture resistance was almost identical for the two materials.

The purpose of this study was to compare the biomechanical performance of commercially available orthopedic gloves to that of a single surgical glove, as well as a double glove system. The orthopedic gloves were found to be thicker than the single surgical glove. This increased thickness of the orthopedic glove was associated with a greater resistance to glove puncture. The thickest orthopedic gloves also had reduced tactile sensitivity when compared to the single surgical glove. In addition, the glove donning forces and glove hydration rates varied considerably. These latter biomechanical performance parameters were not significantly related to glove thickness. The double glove systems tested in this study had similar performance characteristics in regard to many of the orthopedic gloves. The glove donning forces for the double glove systems were the lowest of the gloves tested. In addition, the double glove systems displayed the greatest resistance to glove hydration of the gloves tested. Their performance in the glove hydration tests and the force required to don the double glove systems were much more desirable than any of the orthopedic gloves. The results of this study indicate that the double glove systems may provide a desirable alternative to the use of the single orthopedic gloves.

The purpose of this study was to compare the biomechanical performance of new powder-free commercially available synthetic examination gloves to that of commercially available powder-free latex examination gloves. The synthetic gloves were significantly thinner than the latex gloves. Despite the decreased thickness, all three nitrile gloves, as well as the polyvinyl chloride glove, exhibited a greater resistance to glove puncture. The glove donning forces varied considerably among all gloves, and wet donning forces were greater than dry donning forces. Under dry conditions, the donning forces for the synthetic gloves were less than or equal to the forces for the latex gloves. Because of their increased puncture resistance and similar donning forces, synthetic gloves are a safe alternative to latex examination gloves.

There has been significant research in recent years to analyze and improve the impact behavior and puncture resistance of railroad tank cars. Much of this research has been performed using detailed nonlinear finite element analyses supported by full scale impact testing. This use of detailed simulation methodologies has significantly improved our understanding of the tank impact behaviors and puncture prediction. However, the evaluations in these past studies were primarily performed for a few idealized impact scenarios. This paper describes a research program to evaluate railroad tank car puncture behaviors under more general impact conditions. The approach used in this research program was to apply a tank impact and puncture prediction capability using detailed finite element analyses (FEA). The analysis methodologies apply advanced damage and failure models that were validated by series of material tests under various loading conditions. In this study, the analyses were applied to investigate the tank puncture behaviors for a wide range of impact conditions.

This paper presents part of an investigation on the failure modes in reinforced concrete bridge decks subjected to monotonic static concentrated wheel-loads. The punching shear deck failure appears to be interrelated with a snap-through instability of an “arching” action mechanism activated in the deck. The predicted critical deflection of about 25% of the deck thickness at instability of a two-dimensional laterally restrained three-hinge compressive strut mechanism correlates well with the measured static ultimate deck deflection values of bridge decks that failed primarily in punching. There is also good agreement between the predicted critical applied static concentrated load at instability of the proposed three-hinge truss and the experimental static deck ultimate strength values.

Geomembrane protection materials should be considered in design if geomembranes are to properly serve the role of barrier materials. The type, thickness and properties of the required protection material are in significant need of a rational design method. This series of three papers provides a design method for the inclusion of geomembrane protection materials, geotextiles in particular. Part I focuses on theory, Part II focuses on experiments, and this paper, Part III, focuses on design examples and presents a comparison of results presented in Parts I and II. The design developed in Part II is used in this paper to provide several numerical examples that highlight the different strategies used in Germany and in the USA for the selection of protection geotextiles. This paper also includes a number of design charts for a wide variety of practical situations. Finally, puncture resistance results for a geomembrane with different types of protection materials (other than virgin polymer nonwoven needle punched geotextiles) are presented in the Appendix. The design procedures presented result in a site specific and material specific factor of safety.

Five types of commercial glove liners (within double latex gloves) were compared to single and double latex gloves for cut and puncture resistance and for relative manual dexterity and degree of sensibility. An apparatus was constructed to test glove-pseudofinger constructs in either a cutting or puncture mode. Cutting forces, cutting speed, and type of blade (serrated or scalpel blade) were varied and the time to cut-through measured by an electrical conductivity circuit. Penetration forces were similarly determined with a scalpel blade and a suture needle using a spring scale loading apparatus. Dexterity was measured with an object placement task among a group of orthopedic surgeons. Sensibility was assessed with Semmes-Weinstein monofilaments, two-point discrimination, and vibrametry using standard techniques and rating scales. A subjective evaluation was performed at the end of testing. Time to cut-through for the liners ranged from 2 to 30 seconds for a rapid oscillating scalpel and 4 to 40 seconds for a rapid oscillating serrated knife under minimal loads. When a 1 kg load was added, times to cut-through ranged from 0.4 to 1.0 second. In most cases, the liners were superior to double latex. On average, 100% more force was required to penetrate the liners with a scalpel and 50% more force was required to penetrate the liners with a suture needle compared to double latex. Object placement task times were not significantly longer for subjects wearing liners compared to double latex gloves. Semmes-Weinstein monofilaments, two-point discrimination, and vibrametry showed no difference in sensibility among the various liners and double latex gloves. Subjects felt that the liners were minimally to moderately impairing. An acclimation period may be required for their effective use.

OBJECTIVES: To investigate the cause of an outbreak of needlestick injuries (NSIs) in hospital employees. SETTING: A 700-bed university hospital. DESIGN: Outbreak investigation, laboratory evaluation of a medical waste disposal device, cost analysis. METHODS: Employee health department records were reviewed of workers suffering sticks from needles piercing fiberboard-contaminated material containers (CMCs). A laboratory evaluation of needle-puncture resistance properties of the CMCs was performed using a testing apparatus. The cost of a hospital waste disposal program using fiberboard CMCs was compared with the cost of a program using rigid plastic (polypropylene) boxes. RESULTS: During 40 months of surveillance in 1986 and from 1989 to 1991, only one NSI had occurred from a needle piercing a CMC. During 9 months in 1993, 13 NSIs occurred due to needles piercing CMCs (P < .001). No clinical illness resulted from the NSIs. The outbreak was halted by a temporary change to plastic (polypropylene) boxes for sharps disposal ($4.92 to $23.33/cu ft) until receipt of a box with a newly designed solid fiberboard liner ($1.25/cu ft). CMC liners used during the epidemic had a mean needle puncture resistance of 527 g, as compared with 660 g for liners used before the outbreak (P < .001). The new solid fiberboard liner has a mean puncture resistance of 1,765 g. A program of waste disposal using fiberboard CMCs was found to cost approximately one-seventh the cost of a program using plastic boxes for disposal of infectious waste. CONCLUSION: A program for infectious waste disposal using fiberboard CMCs can be safe and cost-effective if appropriate standards for puncture resistance are met.

Fruit walls as well as nut and seed shells typically perform a multitude of functions. One of the biologically most important functions consists in the direct or indirect protection of the seeds from mechanical damage or other negative environmental influences. This qualifies such biological structures as role models for the development of new materials and components that protect commodities and/or persons from damage caused for example by impacts due to rough handling or crashes. We were able to show how the mechanical properties of metal foam based components can be improved by altering their structure on various hierarchical levels inspired by features and principles important for the impact and/or puncture resistance of the biological role models, rather than by tuning the properties of the bulk material. For this various investigation methods have been established which combine mechanical testing with different imaging methods, as well as with in situ and ex situ mechanical testing methods. Different structural hierarchies especially important for the mechanical deformation and failure behaviour of the biological role models, pomelo fruit (Citrus maxima) and Macadamia integrifolia, were identified. They were abstracted and transferred into corresponding structural principles and thus hierarchically structured bio-inspired metal foams have been designed. A production route for metal based bio-inspired structures by investment casting was successfully established. This allows the production of complex and reliable structures, by implementing and combining different hierarchical structural elements found in the biological concept generators, such as strut design and integration of fibres, as well as by minimising casting defects. To evaluate the structural effects, similar investigation methods and mechanical tests were applied to both the biological role models and the metallic foams. As a result an even deeper quantitative understanding of the form-structure-function relationship of the biological concept generators as well as the bio-inspired metal foams was achieved, on deeper hierarchical levels and overarching different levels.