Advanced finite element cross-country ski boot model for mass optimization directions considering flexion stiffness

Author(s):  
Jurij Hladnik ◽  
Boris Jerman

Flexion stiffness and mass were recognized as two important parameters of energy efficiency for modern top-class ski boots used in skate cross-country skiing. This article summarizes the study on mass optimization of the front foot region of an existing cross-country ski boot, while considering its flexion stiffness. For this purpose, a finite element model of the boot and an artificial foot for simulation of boot flexion stiffness measurement were made. The boot consists of textiles which require specific measurements for their characterization and special finite element material models for their realization. The finite element model was validated through a three-step validation process, in which flexion stiffness of the complete and stripped versions of the finite element model were compared with experimentally acquired flexion stiffness. Flexion stiffness contributions of individual boot components of the front foot region were acquired from the strain energy accumulated in their finite element. Using flexion stiffness and mass contributions and ratios between them (flexion stiffness to mass contributions), directions for flexion stiffness to mass contribution optimization of the boot’s front region were determined. The shoe-upper and shoe-cap were the most efficient regarding their flexion stiffness to mass contribution ratios and were suggested to be thickened. The soles had the highest potential for the boot’s flexion stiffness to mass contribution optimization due to their high mass contribution and relatively low flexion stiffness to mass contribution ratios. As a result, recommendations were made to reduce the soles’ size and/or increase their flexion stiffness to mass contribution ratios. These recommendations are similar to recommendations from a previous study, despite the higher finite element model accuracy and different method used to determine the flexion stiffness contributions.

Akustika ◽  
2019 ◽  
Vol 34 ◽  
pp. 141-147
Author(s):  
Rakhmatjon Rakhmatov ◽  
Vitaliy Krutolapov ◽  
Valeriy Zuzov

The article presents the developed method of determining the attachment points of the mounts of the exhaust system to the vehicle body. The requirements for the construction of a finite element model of the exhaust system are presented, the finite element model of the exhaust system is created, the results of natural frequencies and vibration modes and the strain energy of the structure are shown.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
B. Asgari ◽  
S. A. Osman ◽  
A. Adnan

The model tuning through sensitivity analysis is a prominent procedure to assess the structural behavior and dynamic characteristics of cable-stayed bridges. Most of the previous sensitivity-based model tuning methods are automatic iterative processes; however, the results of recent studies show that the most reasonable results are achievable by applying the manual methods to update the analytical model of cable-stayed bridges. This paper presents a model updating algorithm for highly redundant cable-stayed bridges that can be used as an iterative manual procedure. The updating parameters are selected through the sensitivity analysis which helps to better understand the structural behavior of the bridge. The finite element model of Tatara Bridge is considered for the numerical studies. The results of the simulations indicate the efficiency and applicability of the presented manual tuning method for updating the finite element model of cable-stayed bridges. The new aspects regarding effective material and structural parameters and model tuning procedure presented in this paper will be useful for analyzing and model updating of cable-stayed bridges.


2001 ◽  
Author(s):  
Y. W. Kwon ◽  
J. A. Lobuono

Abstract The objective of this study is to develop a finite element model of the human thorax with a protective body armor system so that the model can adequately determine the thorax’s biodynamical response from a projectile impact. The finite element model of the human thorax consists of the thoracic skeleton, heart, lungs, major arteries, major veins, trachea, and bronchi. The finite element model of the human thorax is validated by comparing the model’s results to experimental data obtained from cadavers wearing a protective body armor system undergoing a projectile impact.


Author(s):  
V. Ramamurti ◽  
D. A. Subramani ◽  
K. Sridhara

Abstract Stress analysis and determination of eigen pairs of a typical turbocharger compressor impeller have been carried out using the concept of cyclic symmetry. A simplified model treating the blade and the hub as isolated elements has also been attempted. The limitations of the simplified model have been brought out. The results of the finite element model using the cyclic symmetric approach have been discussed.


2013 ◽  
Vol 671-674 ◽  
pp. 1012-1015
Author(s):  
Zhao Ning Zhang ◽  
Ke Xing Li

Due to the environment, climate, loads and other factors, the pre-stress applied to the beam is not a constant. It is important for engineers to track the state of the pre-stress in order to ensure security of the bridge in service. To solve the problem mentioned above, the paper puts forward a new way to analyze the effective pre-stress using the displacement inversion method based on the inversion theory according to the measured vertical deflection of the bridge in service at different time. The method is a feasible way to predict the effective pre-stress of the bridge in service. Lastly, taking the pre-stressed concrete continuous rigid frame bridge for example, the effective pre-stress is analyzed by establishing the finite element model.


Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3258 ◽  
Author(s):  
Valery Gupalov ◽  
Alexander Kukaev ◽  
Sergey Shevchenko ◽  
Egor Shalymov ◽  
Vladimir Venediktov

The paper considers the construction of a piezoelectric accelerometer capable of measuring constant linear acceleration. A number of designs are proposed that make it possible to achieve high sensitivity with small dimensions and a wide frequency band (from 10−5 Hz). The finite element model of the proposed design was investigated, and its output characteristic and scale factor (36 mV/g) were obtained.


2019 ◽  
Vol 71 (1) ◽  
pp. 54-60 ◽  
Author(s):  
Shixian Xu ◽  
Zhengtao Su ◽  
Jian Wu

Purpose This paper aims to research the influence of pressure, friction factors, roughness and actuating speed to the mixed lubrication models of outstroke and instroke. Design/methodology/approach Mixed lubrication model is solved by finite volume method, which consists of coupled fluid mechanics, deformation mechanics and contact mechanics analyses. The influence of friction factor on the finite element model is also considered. Then, contact pressure, film thickness, friction and leakage have been studied. Findings It was found that the amount of leakage is sensitive to the film thickness. The larger the film thickness is, the greater the influence received from the friction factor, however, the effect of oil film on the friction is negligible. The friction is determined mainly by the contact pressure. The trend of friction and leakage influenced by actuating velocity and roughness is also obtained. Originality/value The influence of friction factor on the finite element model is considered. This can make the calculation more accurate.


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