Slip Resistance Research Articles

Experimental study on the longitudinal resistance of WJ-8 fasteners subjected to torque and vertical loading in continuously welded rails

The key functions of the fastener system are to hold the rail against the sleepers and to restrain the rail from all forms of movements that could lead to loss of geometry and stability of the track. Thus, fastener resistance is an important parameter in the continuously welded rail technology. This study investigates the characteristics of the longitudinal resistance of WJ-8 fasteners subjected to varying torques and vertical loadings. The vertical loading was applied to the rail section through a reaction frame, while the torque was applied using a digital torque wrench. Two types of fasteners, conventional-resistance and small-resistance fasteners, were tested in this study. The study shows that: (1) The growth rate of the longitudinal resistance of the fastener is independent of the vertical loading until the fastener slips. (2) The slip resistance of fasteners increases as the torque and vertical loading are increased. (3) The relationship between the longitudinal resistance and the displacement of fasteners at varying torques and vertical loadings fits a power index function. (4) The relationship between the longitudinal resistance and the displacement of the fastener exhibits hysteresis. The study serves as a reference for verifying and improving future calculation methods for the longitudinal resistance of fasteners in continuously welded rails.

Experimental characterization and crystal plasticity modeling of anisotropy, tension-compression asymmetry, and texture evolution of additively manufactured Inconel 718 at room and elevated temperatures

In this work, strength and microstructural evolution of superalloy Inconel 718 (IN718) are characterized as a function of the initial microstructure created via direct metal laser melting (DMLM) additive manufacturing (AM) technology along with subsequent hot isostatic pressing (HIP) and heat treatments as well as wrought processing. Stress-strain curves are measured in tension and compression from room temperature to 550 °C and crystallographic texture is characterized using neutron diffraction. Furthermore, a recently developed crystal plasticity model incorporating the effects of precipitates is extended to interpret the temperature dependent deformation behavior of the alloy. The model accounts for solid solution, precipitate shearing, and grain size and shape contributions to initial slip resistance, which evolves with a dislocation density-based hardening law considering latent hardening, while non-Schmid effects are taken into account in the activation stress. Part of the experimental data is used for calibration of the model, while the rest is used for experimental validation of the model. It is shown that the model is capable of modeling the data with accuracy. Based on the comparison of the data and model predictions, it is inferred that the grain structure and texture give rise to plastic anisotropy of the alloy, while its tension-compression asymmetry results from non-Schmid effects and latent hardening.

Quantitative Characterization of the Aqua-Dispersing Nano-Binder Effects on the Slip Resistance of Borrowed Soil of a Rock Slope

Soil loss can be reduced by enhancing the slip resistance of soil. Therefore, the slip resistance of borrowed soil of rock slopes is key to ecological restoration. An effective way to enhance the soil slip resistance is to improve the permeability and shear strength of the soil by using polymeric materials. Most current projects have confirmed the amount and effect of additions via repeated tests because of the lack of a quantitative characterization model. This leads to high implementation costs and inhibition of the method’s popularization and application. Therefore, based on different dosages and application processes of aqua-dispersing nano-binder (ADNB), the present study aims to examine the change rules of the particles, permeability, and shear strength after soil improvement through particle analysis, permeability, and direct shear experiments. It was found that ADNB could increase the average particle diameter, permeability coefficient, and shear strength of soil, and significantly enhanced the slip resistance of rock slope soil. On this basis, this paper establishes quantitative characterization models of the slip resistance of rock slopes, reveals the clay improvement mechanism, and proposes the optimal addition range. The study also verified the reliability of the models through an engineering application. It is proved that the appropriate amount of ADNB based on the model can enhance the slip resistance of borrowed soil as well as the ecological restoration effect of rock slopes. The model in question solves the problem of repeated tests during implementation due to the lack of a quantitative characterization model and provides theoretical guidance for the ecological restoration of rock slopes.

A molecular perspective to analytical modeling that reveals new instabilities in dielectric elastomer transducers

We use a four-parameter material model for polymers - the Edward–Vilgis (EV) model, which models polymeric crosslinks, sliplinks, slippage and inextensibility to analyze dielectric elastomers (DEs). The EV model allows us to investigate the DE response from a molecular perspective, revealing new instabilities in DEs, primarily due to sliplinks. We compare the EV model with the Gent model – a crosslink-only model commonly used in the field of DE, on its ability to fit the non-linear stress–strain response of an acrylic elastomer (VHB 4905), which contains a significant amount of entanglements. We found that the EV model provided an excellent fit to the strain softening phenomenon at small to modest strains, which is missed by the Gent model. Slippage of sliplinks at these regions of strain produces slip resistance that contributed to enhance the resistance to applied forces. Subsequent slip relaxation due to the uncoiling of entanglements will lead to significant strain softening, giving the DE a higher susceptibility to mechanically and electro-mechanically-induced instabilities. From our analyses, we produced mechanical stability phase plots and electromechanical stability design plots, for elastomers of different sliplink-to-crosslink compositions. Such plots may serve as guides to develop dielectric elastomers with desired material properties and performances, and tailor to specific applications.

The effect of nano-silica material and alkali resistant glass fibre on the OGFC asphalt mixture

ABSTRACT The main objective of this study is to improve the physical and mechanical properties of open-graded friction courses (OGFCs). Therefore, the combination of nano-silica (NS) material and alkali resistant (AR) glass fibre was used as additives. The effects of these materials were evaluated on the OGFC mixtures by laboratory tests including draindown, cantabro abrasion test, porosity, permeability, slip resistance, indirect tensile strength (ITS), moisture susceptibility (TSR) and dynamic creep tests. Draindown tests were conducted on different mixtures including 4% NS by weight of the asphalt binder, 0.1% and 0.2% AR-glass fibre by weight of the mix and 5.5% and 6.5% asphalt binders by weight of mix. The results showed that the combination of 4% NS material, 0.2% AR-glass fibre and 5.5% asphalt binder is suitable and reduces the draindown significantly. The test results showed that, while the use of this compound in OGFC led to a reduction of porosity by only about 12%, cohesion resistance, slip resistance, wet and dry ITS and rutting resistance of OGFC were increased by about 50%, 16%, 30% and 50%, respectively. Also, due to the relatively similar effects of this combination on the wet and dry ITS, the percentage of TSR increased by a very small amount (about 3%).

Microstructure and texture evolution in Mg/Nb layered materials made by accumulative roll bonding

In this work, lamellar composite sheets combining one of two fully hexagonal magnesium-lithium alloys (Mg–4Li and Mg–5Li wt%) and pure niobium (Nb) are manufactured via accumulative roll bonding (ARB). With extreme straining of over two true strain, the individual layers were refined to 200 μm. The strength differential between co-deforming phases with strain is characterized to be low enough to facilitate bonding without instabilities. Additionally, homogeneity in deformation was enhanced by intermediate annealing, especially for the Mg-xLi phase. Diffraction methods and polycrystal modeling are employed to study the microstructure and texture evolution of the individual phases after each subsequent ARB pass. Characterization by electron backscatter diffraction and neutron diffraction reveals substantial changes in microstructure and texture in both phases and very little deformation twinning in the Mg-xLi phase. Evolution of grain morphology and the number of grains that span a layer with ARB and annealing are determined and discussed. To link texture evolution to slip-based deformation mechanisms during the processing, a multiscale polycrystalline model of the two-phase Mg–4Li/Nb composite was developed, which included a relative directional compliance (RDC) method to account for anisotropic interactions in the phases, allowing appropriate slip sensitivity to dislocation density based hardening on the multiple slip modes in Mg–4Li and in Nb. The model indicates that the deformation of the Mg–4Li phase during ARB cycles was accommodated by more basal <a> and progressively smaller amounts of prismatic <a>, pyramidal <c+a>, and twinning than previously reported for rolling of Mg–4Li. The experimental textures cannot be entirely explained by grain shape and an increase in pyramidal and prismatic slip resistance are required as expected with a small grain size. Consistent with measurements, the model predicts that c-axis of the Mg–4Li phase tilts from the sheet's normal direction towards the rolling direction, and that the strong γ-fiber and the unusually weak α-fiber should develop in Nb with large ARB straining of the Mg-xLi/Nb composites.

Theoretical analysis of anchorage mechanism for rock bolt including local stripping bolt

We have proposed a theoretical model for the analysis of bolt anchorage effects through cross-section uniformity and elastic theory. When the surrounding rock and soil are fixed, then the slip resistance forces directly proportional to the displacement of the bolt. An equilibrium differential equation for the wholly bolt has been established. The axis stress expression has been presented from the combined boundary conditions. It is a monotonic function which consists of negative index and minus index function of the distance, away from the force. The effects of friction proportional coefficient and radius have been analyzed as well. For local stripping bolt, a different model having separate parts has also been analyzed. We have also deduced the axis stress distribution function. Moreover, the curves of different separate conditions were compared which conclude that there is a terrace for the separate part. The longer the separate part, the quicker the axis stress decreased. Finally, an experiment has been performed which show the distribution of axis stress has the same trend with the strain gauge record. The theory solution of axis stress is also proved to be reasonable.

Characteristics of natural rubber/latex compound waste (NR/LCW) blends in the perspective of shoe soles application

Being difficult to degrade, latex compound waste (LCW) should be handled carefully. In this study the possibility of application of LCW for shoe sole was evaluated. LCW was derived from latex-based industry from local factory. It was blended with natural rubber (NR) with the ratio ranging from 100/0; 90/10; 80/20; 70/30; 60/40 and 50/50. Cure characteristics and mechanical properties including tensile strength, elongation at break, hardness and tear strength, were measured before and after aging. Abrasion loss and slip resistance were also taken account. The results finding showed that crosslink density of the NR/LCW blends were higher than of control. Mechanical properties of the blends were greatly affected by crosslink density. Compared to control, the NR/LCW blends provided lower tensile and elongation, but higher in tear strength, hardness and abrasion loss. Heat aging tended to decrease the mechanical properties. LCW improved the coefficient of friction (CoF).

Enhancing bamboo reinforcement using a hose-clamp to increase bond-stress and slip resistance

Bamboo can be used as reinforcement for concrete, especially in simple construction, because of its high tensile strength. Any collapse that occurs in a bamboo reinforced concrete beam is often caused by failure of the bond between bamboo and concrete. Many researchers have suggested using adhesive coatings or roughness modifications to bamboo reinforcement, but a slip failure pattern still appears. The aim of this research is to increase bond-stress and slip resistance by using a hose-clamp, and to obtain a relationship model of load vs. deflection and bond-stress vs. slip between bamboo reinforcement and concrete. The experiments use 75 mm × 150 mm x 1100 mm concrete beams. Concrete beam specimens comprise 24 bamboo-reinforced beams, one beam with 8 mm diameter steel reinforcement, and one without reinforcement. Hose-clamp spacing varies by 0 cm, 15 cm, 20 cm, and 25 cm. Beam testing uses a four-point loading method. Test results show an increase in bond-stress and flexural capacity, and reduced slip between bamboo reinforcement and concrete, when hose-clamps are used. There are differences in the relationship of load vs. deflection and bond-stress vs. slip between bamboo reinforced concrete beams and steel reinforced concrete beams.

A novel method to improve vehicle energy efficiency: Minimization of tire power loss

The importance of energy efficiency, as one of the most crucial issues in automotive industry, has grown more rapidly considering the global energy crisis and climate change in recent years. This paper aims to introduce a method to increase the powertrain efficiency based on the minimization of tire power loss. Slip resistance is taken into account as well as rolling resistance to yield the modified tire resistance considered in this study. It is shown that the general optimal control problem can be reduced to an instantaneous minimization problem in which the equivalent force of tire power loss is to be minimized at each instant of time. Moreover, tire inflation pressure is selected as the control input bearing its major influence on tire resistance and its potential of being controllable in the mind. In addition, a polynomial inverse tire model is developed in order to find the solution of the minimization problem with lower computational cost. The coefficients used in inverse tire model are characterized as a function of friction coefficient, normal load, and inflation pressure so that the reliability and accuracy of the model are guaranteed under different conditions. The effectiveness of the proposed online control system, called Tire Inflation Pressure Regulation System, is simulated in some driving cycles, i.e. NEDC, FTP, HWFET, and ARTEMIS-Urban, and it is shown that up to 2% improvement is achievable.

Asymmetric cyclic response of tensile pre-deformed Cu with highly oriented nanoscale twins

History-independent, stable and symmetric cyclic response has been detected in as-deposited bulk polycrystalline Cu with highly oriented nanotwins [Nature 551 (2017) 214–217]. In this study, to deepen the understanding of cyclic deformation in nanotwinned (NT) structures, small levels of tensile pre-strains were applied on NT-Cu, followed by strain-controlled symmetric tension-compression cyclic tests. Distinct from the symmetric cyclic response of as-deposited NT-Cu, the magnitude of the maximum stress in tension is much larger than that of the minimum stress in compression, indicating that the cyclic response of tensile pre-deformed NT-Cu is highly asymmetric. The degree of its cyclic asymmetry gradually decays as the number of cycles or the plastic strain amplitude is increased. The tensile pre-deformed NT-Cu recovers to its symmetric cyclic response after cyclic deformation at sufficiently large plastic strain amplitude, analogous to that detected in as-deposited NT counterparts. Molecular dynamics simulations and microstructural observations revealed that the observed asymmetric cyclic response is mainly related to the activation and movement of threading dislocations with extended misfit dislocation tails lying on the twin boundaries (TBs) during tensile pre-deformation. During cyclic deformation, threading dislocations in adjacent twin interiors tend to link their long tails with one another to form correlated necklace dislocations (CNDs) with a symmetric structure. The CNDs move back-and-forth along the twin boundaries without directional slip resistance, contributing to the transition from asymmetric to symmetric cyclic response of NT-Cu.

ALTERNATIF PENGGUNAAN SERAT ECENG GONDOK PADA CAMPURAN STONE MATRIX ASPHALT GRADASI HALUS MENINGKATKAN STABILITAS CAMPURAN ASPAL PANAS

AbstractRoads are one of the transportation infrastructure that is needed for everyday life so that the road conditions have durability according to the age of the plan. For this reason a technology for road construction that has structural value has been born. Stone Matrix Asphalt (SMA) is a type of hot paved mixture that is used as a surface layer with a number of coating characteristics that can provide benefits for motorists because of its high slip resistance. In this mixture using cellulose fibers derived from water hyacinth to find out whether water hyacinth fiber can be used as a mixture of hot asphalt and as a substitute for cellulose fibers in the market. In this study, the laboratory experimental research method is used to conduct experimental activities to produce a result of water hyacinth fiber mixing with Marshall Properties. The purpose of this experiment is to compare the results obtained at optimum levels in the specifications of SNI Specifications for Stone Matrix Asphalt (SMA) 2015, with the addition of water hyacinth fiber variations of 1%, 2%, 3%, 4%, 5% taken from asphalt content . The final result of this study was Marshall evaluation where Stability was 55830.18 kg on 3% water hyacinth fiber content, 17.09% VIM on 5% water hyacinth fiber content, 172.40% VMA on 5% water hyacinth fiber content, VFWA 2100.28% on 0% water hyacinth fiber content, 2.23 mm flow on 4.9% water hyacinth fiber content, Marshall Quotient 25984.39 kg / mm on 3% water hyacinth fiber content. These results indicate that water hyacinth fiber cannot be used in a mixture of SNI 2015 Stone Matrix Asphalt Specifications (SMA). Keywords: Water Hyacinth Fiber, Stone Matrix Asphalt, Marshall Properties

Modeling of twinning-induced plasticity using crystal plasticity and thermodynamic framework

In many applications of steels, especially in aerospace and petroleum industry, large deformation is required in order to achieve complex shape and geometry of finished products. In these, advanced high-strength steels play a vital role by attaining favorable amalgamation of high strength and ductility. Among all second-generation steels, twinning-induced plasticity contains a significant percentage of austenite phase, shows outstanding tensile strength and ductility. The primary cause of having these outstanding properties is found to be stress-assisted austenite to martensite phase transformation, commonly described as twinning. In this paper, a micromechanical model is developed in the thermomechanical framework to investigate elastic–plastic deformation of twinning-induced plasticity steel. It is assumed that plastic deformation is caused due to slip and mechanical twinning under given loading conditions. Firstly, a micromechanical constitutive model, considering slip and mechanical twinning as sources of permanent deformation, is developed by kinematic decomposition of an austenite crystal into intermediate configurations. Secondly, a thermodynamic framework is used to formulate driving potentials for slip and twinning mechanisms. Thirdly, the developed model is numerically implemented into finite element software ABAQUS by a user-defined material subroutine. Finally, the deformation behavior of single and polycrystalline austenite are predicted by numerical simulations in tension compression, and simple shear loading conditions. It is found that in tension twin deformation plays a dominant role, while the reverse is observed in compression. In simple shear, on an activation of twin mode, slip systems encounter higher slip resistance due to slip–slip and slip–twin interactions.

PNADIS: An automated Peierls–Nabarro analyzer for dislocation core structure and slip resistance

Dislocation is one of the most critical and fundamental crystal defects that dominate the mechanical behavior of crystalline solids, however, a quantitative determination of its character and property in experiments is quite challenging and limited so far. In this paper, a fully automated Peierls–Nabarro (P–N) analyzer named PNADIS is presented; a complete set of the character and property of dislocation can be automatically derived, including the dislocation core structure, Peierls energy and stress, pressure field around dislocation core, solute/dislocation interaction energy, as well as the energy barrier and increase in critical-resolved shear stress at 0 K for solid solution strengthening. Furthermore, both one-dimensional (1D) and two-dimensional (2D) P–N models are implemented to meet the demand to analyze the character and property of dislocation for not only simple FCC and HCP structures but also complex crystals. The implementation of this code has been critically validated by a lot of evaluations and tests including 1D P–N model for complex crystals, 2D P–N model for FCC and HCP metals, pressure field around dislocation core, and solid solution strengthening for alloys. We expect that the automated feature of this code would provide a high-efficiency solution for determining the character and property of dislocation. Program summaryProgram title: PNADISProgram Files doi:http://dx.doi.org/10.17632/whk6wdy3nn.1Licensing provisions: GNU General Public License 3Programming language: MATLABNature of problem: To determine automatically the character and property of dislocation, including dislocation core structure, Peierls stress, pressure field around dislocation core and solid solution strengthening, for not only FCC and HCP structures but also complex crystals.Solution method: The generalized stacking fault energy is firstly fitted by Fourier expansion, and meanwhile an appropriate trial function of disregistry vector is chosen. Afterwards, a least square minimization of the difference between elastic resistance and restoring force for one-dimensional Peierls–Nabarro model, or a global minimization of the total dislocation energy via particle swarm optimization or genetic algorithm for two-dimensional Peierls–Nabarro model, will be performed to determine the dislocation core structure of complex crystals, or FCC and HCP structures. Finally, the Peierls stress, pressure field around dislocation core and solid solute strengthening are derived from the calculated dislocation core structure.

Material Characterization for Sustainable Concrete Paving Blocks

Recycled aggregates have been widely studied and used in concrete products nowadays. There are still many waste materials that can be used as recycled aggregates other than crushed concrete particles. This paper aims to study the property variations of sustainable concrete paving block incorporating different contents of construction wastes. Five different types of waste materials were used in this project, including: recycled concrete coarse aggregate (RCCA), recycled concrete fine aggregate (RCFA), crushed glass (CG), crumb rubber (CB), and ground granulated blast furnace slag (GGBS). According to the test results of the properties of blocks mixed with different levels of wastes materials, it is concluded that adding both RCCA and RCFA in the block can decrease its strength and increase the water absorption. The suggested replacement levels for RCCA and RCFA are 60% and 20%, respectively. Mixing crushed glass in the concrete paving blocks as a type of coarse aggregates can improve the blocks’ strength and decrease the blocks’ water absorption. Addition of crumb rubber causes a significant deterioration of blocks’ properties except for its slip resistance.

Effects of cold rolling reduction ratio on microstructures and tensile properties of intercritically annealed medium-Mn steels

The relationship between the cold rolling reduction ratio of medium-Mn steel before annealing, and the microstructure and tensile properties after annealing was investigated. The model alloy (Fe8Mn–0.2C3Al (wt.%) steel) was cold-rolled at different reduction ratios (between 0% and 60%) prior to intercritical annealing (IA) at 720 °C for 30 min. An increase in the cold rolling reduction ratio caused the nanolaminate morphology (α′ tempered martensite (α′temp) and retained austenite (γR) phases) to change to a nanoscale globular morphology (ferrite (α) and γR phases). However, the volume fraction of the γR phase, width of the nanolaminate phase, and the diameter of the nanoscale globular phase remained essentially unchanged, regardless of the cold rolling reduction ratio. The nanolaminate morphology exhibited a crystallographic orientation characterized by the absence of α′ recrystallization and austenite memory effect, that is preferable to the nanoscale globular morphology. The steel that was cold-rolled at a higher reduction ratio had a higher yield strength due to the increased slip resistance of the phases (consisting of a reduced area of the same orientation). In addition, with an increase in the cold rolling reduction ratio, the tensile strength and total elongation were improved owing to the more dynamic transformation- and twinning-induced plasticity in the nanoscale globular γR phase than the nanolaminate γR phase. Therefore, we have concluded that an optimized cold working prior to IA, will lead to improved mechanical properties of industrially produced medium-Mn steel.

Effect of groove width and depth and urethane coating on slip resistance of vinyl flooring sheet in glycerol solution

Abstract Sheet-type resin floors possess a risk of slipping during rains or liquid spills. We investigated the friction properties of vinyl flooring sheets using shoes and glycerol solution, and clarified the combined effect of the groove's depth and width and a urethane coating on the coefficient of friction (COF). According to the analysis, the static COF could be expressed using the spreading coefficient. All the dynamic COFs could be expressed using the spreading coefficient and aspect ratio of the grooves. All the COFs were significantly affected by the interfacial tension at the triple line but were relatively unaffected by the groove shape.

On the work hardening of titanium: new insights from nanoindentation

Nanoindentation was used to probe the local slip resistance in CP-Ti deformed in compression to different extents. Changes in hardness in the deformed grains and twins were compared with the change in flow stress measured during deformation, with the aim to elucidate the relative contribution of slip and twinning to the work hardening of Ti alloys. The hardness values were calibrated with measurements on binary Ti–Al alloys. The hardness increased only slightly with deformation and cannot explain the observed work hardening. Although twinned regions were found to be harder than the parent grains, this increase was found to be small once the effect of crystal orientation was accounted for. The increase in hardness in the twins was slightly higher for compressive twins than for tensile twins. It is proposed that this modest hardness increase in the twins is more consistent with the presence of twinning stresses than with a change in the local flow stress caused by dislocation interactions. The implications of these findings to the work hardening of CP titanium are discussed.

Seismic performance of cold-formed steel bolted moment connections with bolting friction-slip mechanism

Typical cold-formed steel (CFS) moment-resisting connections generally have relatively low ductility and energy dissipation capacity as a result of low local/distortional buckling resistance of thin-walled CFS elements, and therefore, may not be suitable for seismic applications. To address this issue, a comprehensive analytical study is presented on the seismic performance of CFS bolted beam-to-column connections with fiction-slip mechanism aiming to obtain more efficient design solutions suitable for CFS frames in seismic regions. Experimentally validated finite element (FE) models in ABAQUS are used to predict the hysteretic behaviour and failure of a range of CFS connections by taking into account the characteristics of the bolting system as well as nonlinear material properties and geometrical imperfections. The developed models are then used to investigate the effects of CFS beam cross-sectional shape and classification, bolt configuration, and slip resistance on the seismic performance of the connections. It is shown that using bolting friction-slip mechanism can significantly increase (up to 200%) the ductility, energy dissipation capacity and damping coefficient of the connections especially for CFS beams with thinner plates (class 3 and 4). Based on the results, the best design configurations are identified to improve the cyclic response of the CFS connections under strong earthquakes. While conventional bolted moment connections with class 3 and 4 beam cross-sections generally do not satisfy the AISC requirements for intermediate and special moment frames, it is shown that optimum designed connections with bolting friction-slip mechanism can be efficiently used in high seismic regions.

Slip resistance and wearability of safety footwear used on icy surfaces for outdoor municipal workers.

BACKGROUND:Outdoor workers experience high injury rates in the winter due to slipping on ice and snow. Our testing program has demonstrated that most safety footwear does not provide adequate slip-resistance and/or comfort in icy conditions.OBJECTIVE:Our objective was to determine which of the most commonly worn safety footwear available to outdoor municipal workers in Toronto, Ontario, Canada would best prevent slips on icy surfaces and which models had good wearability.METHODS:We selected 45 of the most popular types of winter footwear worn by these workers and applied our Maximum Achievable Angle (MAA) test method to rate the slip-resistance of the footwear. A ten-point rating scale was used for recording participants’ perceptions of wearability. The MAA test measured the steepest ice-covered incline that participants can walk up and down without experiencing a slip.RESULTS:Of the 45 types of footwear tested, only one model achieved an MAA score of 8 degrees that exceeded our cut-off for acceptable performance set at 7 degrees. Secondary measures of performance including thermal insulation; wearability and heaviness of footwear tested were also ranked.CONCLUSION:Our results demonstrate that footwear manufactures have the opportunity to differentiate their footwear by investing in slip-resistant outsole materials.