Numerical Simulation of Quasi-Static Compression Behavior of the Toe Cap Component for Safety Footwear

Abstract

Abstract-Geometrical changes can improve stiffness substantially. The project S3 -Safety Slim Shoe presents the potential to reduce the weight in safety toe cap components combining a new geometric redesign deeply associated to local stiffeners to realize the full potential of AHSS -Advanced High Strength Steels. The investigation aimed to examine the potential energy absorption capacity for a substantial thickness reduction of slim toe cap models. In this paper the normative quasi-static compression test in the context of the experimental validation of the two last and approved prototype models were focused. A non-linear FEA -Finite Element Analysis of the elasto-plastic deformation mode was performed, and several numerical parameters such as: hardening effects of extrapolated True-Stress-Strain material curves and simulation convergence conditions were carried out. Experimental results of the toe cap deformation behavior confront a weight saving range of over 40%, compared with the original steel toe cap.

Assessing the Compressive and Impact Behavior of Plastic Safety Toe Caps through Computational Modelling

“…A comparison between the Force-displacement (F-d) curve resulting from the compression test and the one obtained numerically is made in Figure 16. A similar trend for the same curve was obtained in Dirksen et al [31] and Costa et al [15]. In the F-d curve of the tested toe cap, the maximum loading displacement recorded at 15 kN was 6.12 mm and for the simulation curve was 5.79 mm.…”

“…An overshoe protector that comprises this toe cap alongside a cover made of aramid fabric and TPU resin was also presented, resulting in the creation of a 56% lighter solution than steel counterparts, that were approved in an impact test done with 100 J. Several studies are also reported in the field of metallic toe caps, where different grades of steel and geometries were tested, resulting in an up to 50% thickness and weight saving when compared to their initial designs [15,23,[27][28][29]. Although non-metallic solutions present promising results, a number of challenges remain related to material development, design optimization, and speed and ease of manufacturing, while keeping production cost comparable to current metallic solutions.…”

“…Design optimization through computational modeling is reported for metallic [15,23,[27][28][29][30][31]] and non-metallic toe caps [19,21,25], resulting in a reduction of weight by 50% with thickness reduction compared to traditional solutions. Since the introduction of CAD/CAE tools, optimization of product design has been an ongoing pursuit.…”

“…Although, it is possible to manufacture thin steel toe caps, its high density makes this component one of the main contributors to the total shoe weight. In most cases, this component can represent up to 35% of the total mass of the shoe, thus contributing to user fatigue and leading to the rejection of this kind of PPE [15].…”

In shoe pressure measurements during different motor tasks while wearing safety shoes: The effect of custom made insoles vs. prefabricated and off-the-shelf

“…Despite the increasingly strict regulations on safety shoes quality, which promote to minimize injuries and loss of working days, and the increasing rate of foot and musculoskeletal ailments reported in factory workplace, very little has thus far been investigated to improve workers' comfort and to increase our understanding on the biomechanics of the foot inside safety shoes. Safety shoes have been tested for the properties of their materials and components [25], slip resistance [26], and comfort [19,22]. The effects of custom insoles on different musculoskeletal diseases have also been extensively reported [13,14,16].…”