A numerical simulation of static stiffness and strength of circular saw blade

The paper deals with the evaluation of the static stiffness and strength, which are critical parameters affecting the stability of the machining process but also the safety and durability of the wood cutting tools. Circular saw blade models for the purpose of computer numerical simulation were proposed using finite element methods, and verified in earlier research. Deformation response was observed, depending on the input parameters correlating to the saw blade woodworking conditions. The strength of the saw blade was compared with the different clamping methods and different thickness of the circular saw blade. An article gives a disturbing finding how minor change in the quality of the circular saw blade clamping, specifically one degree of misalignment, leads to critical states and probable cause of damage. © 2018 The Authors, published by EDP Sciences

Comparaison de la morphologie du pied entre les enfants chinois et mongoliens

Knowledge of foot morphology is fundamental to optimize children’s footwear design. The aim of this study is to compare the foot morphology of Chinese and Mongolian children from 7 to 14 years old. Relative data of 339 Mongolian children and another matched 379 Chinese children were collected using 3D foot scanner. The findings of this study are as follows: i) the absolute foot length of Chinese children is significantly greater than that of Mongolian children of the same age; ii) Mongolian children show significantly greater heel width, toe thickness, lateral malleolus height, instep height and ball girth compared to Chinese children of the same age. The foot width of Chinese children is significantly greater than that of Mongolian children of the same age; iii) Chinese children have a higher risk of hallux valgus than Mongolian children of both sexes. Small variations in foot morphology discussed in this paper could be useful when considering the shoes design for Mongolian and Chinese children. © 2020 by the author(s)

Transfert de charge en fonction de la vitesse de course pour les coureurs du sexe masculin qui touchent le sol avec l’arrière-pied

The purpose of this study was to identify the influence of running speed on plantar pressure, and to use a load transfer algorithm to investigate the load transference in healthy recreational male runners who had a natural rear-foot strike pattern. Totally, 49 healthy males participated in this study, 39 of them (age 22.8 ± 1.8 years, weight 65.6 ± 7.9 kg, height 171.9 ± 4.0 cm) were identified as rear-foot strike runners. Data of pressure parameters, including maximum force, peak pressure, contact area and force-time integral (FTI) was recorded by Pedar-X insole plantar pressure measurement system at 8 different speeds (5, 6, 7, 8, 9, 10, 11, 12 km/h). The results indicated that with the increase of running speed, plantar pressure significantly increased under all foot regions except for the big toe. Faster running speeds resulted in significant lower FTI in all foot regions except for lateral midfoot and heel. Medial metatarsal, central metatarsal, and big toe were the main loading regions for rear-foot strike male runners during running. Load transferred from medial foot to lateral foot in transverse direction, and from toes to metatarsal, midfoot and heel in the longitudinal direction with increasing speeds. As a component of the spring mechanism, the arch played a key role in supporting and transferring loads. © 2020 by the author(s)

On flexural stiffness of polymer sandwich walls

This paper deals with the flexural stiffness of sandwich structures based on fiberglass and polymeric foams. The influence of geometrical and material parameters on the resulting effective flexural stiffness of the sandwich structure is being studied experimentally, analytically and using FEM models. The effective elasticity module of the sandwich-structured element is being studied and it’s theoretical and model dependencies on the stiffness of the foam core are being investigated. These dependencies are then compared with experimentally observed values. This study shows it is necessary to pay special attention to the issue of flexural stiffness of walls when designing sandwich shell products in order to prevent possible failures in the practical applications of these types of structures. © 2016 Trans Tech Publications, Switzerland

Load transference with the gain of excessive body mass: A two-year longitudinal study

Previous studies investigating the effect of excessive weight on the foot have commonly been cross-sectional; therefore, it is still unclear how the foot function gradually changes with the increased body mass that is physiologically gained over time. This study aimed to use a load transfer method to identify the mechanism of how the foot function changed with the increased excessive body mass over two years. Taking normal weight as the baseline, fifteen children became overweight or obese (group 1), and fifteen counterparts maintained normal weight (group 0) over the two years. Barefoot walking was assessed using a Footscan® plate system. A load transfer method was used based upon the relative force–time integral (FTI) to provide an insight into plantar load transference as children increased in weight. Significantly increased FTIs were found at the big toe (BT), medial metatarsal (MM), lateral metatarsal (LM), and lateral heel (HL) in group 1, while at BT, MM, medial heel (HM), and HL in group 0. Foot load showed a posterior to anterior transferal from midfoot (2.5%) and heel (7.0%) to metatarsal and big toe in group 1. The control group, however, shifted the loading within the metatarsal level from LM to HM (4.1%), and equally relieved weight from around the midfoot (MF) (3.0%) to BT, MM, HM and HL. Earlier weight loss intervention is required to prevent further adverse effects on foot functions caused by excessive weight-bearing. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Footwear manufacturing

The chapter contains basic footwear classification into the categories according to different kriterias. The reader will be provided by basic knowledge of shoe manufacturing process and the difference of assembling technologies. The last part is focused on norm time management. This lesson should clarify the basic terms of shoe parts and the manufacturing process as well.

Lasts

In this chapter, the reader will acquire a basic classification of the last according to various distinguishing criteria, become acquainted with production issues and the most frequent occurrence of defects originating either during production of the last itself as well as related to the incorrect use of a last. Considering the fact that a last is approximately the shape of a human foot, the student will become acquainted with the method for measuring the foot, with marking last or footwear size and also marginally the possible impact of the last on the feet of future wearers of the shoe.

Textile

The chapter TEXTILE very briefly classifies and describes the basic textile raw materials used in shoe and haberdashery industry. Few articles are focused on the special textiles which are based on the use of membranes with the water or UV protection.

The impact of exercise on school children with valgus heel and flatfeet

Studie popisuje vliv některých cviků na rozložení nášlapných sil u 35 probandů, kteří trpí nadměrnou pronací a někteří i plochou nohou. Po treninku došlo k přesunu zátěže z vnitřní na vnější stranu chodidla.The study about the impact of remedial exersice on the plantar pressure of 35 subjects suffering from excessive pronation. After training the plantar load shifted from medial to lateral side

Appropriate exercise and correct gait as a needful supplement in treatment of excessive pronation and flat foot

Uvedená studie sleduje změny v zátěži nohou vlivem různých nápravných cvičení u probandů s valgosním postavením pat.The present study investigated the acute foot loading changes of remedial exercise modifications in subjects suffering from excessive pronation and flat foot