Effects of Insoles and Additional Shock Absorption Foam on the Cushioning Properties of Sport Shoes

2007 ◽  
Vol 23 (2) ◽  
pp. 119-127 ◽  
Author(s):  
Hung-Ta Chiu ◽  
Tzyy-Yuang Shiang
Keyword(s):  
Potential Energy ◽  
Impact Energy ◽  
Energy Condition ◽  
Impact Testing ◽  
Shock Absorption ◽  
Absorption Effect ◽  
Testing Conditions ◽  
Testing Method

The purpose of this study was to investigate the effects of insoles and additional shock absorption foam on the cushioning properties of various sport shoes with an impact testing method. Three commercial sport shoes were used in this study, and shock absorption foam (TPE5020; Vers Tech Science Co. Ltd., Taiwan) with 2-mm thickness was placed below the insole in the heel region for each shoe. Eight total impacts with potential energy ranged from 1.82 to 6.08 J were performed onto the heel region of the shoe. The order of testing conditions was first without insole, then with insole, and finally interposing the shock absorption foam for each shoe. Peak deceleration of the striker was measured with an accelerometer attached to the striker during impact. The results of this study seemed to show that the insole or additional shock absorption foam could perform its shock absorption effect well for the shoes with limited midsole cushioning. Further, our findings showed that insoles absorbed more, even up to 24–32% of impact energy under low impact energy. It seemed to indicate that insoles play a more important role in cushioning properties of sport shoes under a low impact energy condition.

scholarly journals Application of Glass Fiber and Carbon Fiber-Reinforced Thermoplastics in Face Guards

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 18
Author(s):  
Takahiro Wada ◽  
Hiroshi Churei ◽  
Mako Yokose ◽  
Naohiko Iwasaki ◽  
Hidekazu Takahashi ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Glass Fiber ◽  
Impact Testing ◽  
Fiber Reinforced ◽  
Shock Absorption ◽  
Glass Fiber Reinforced ◽  
Field Of Vision ◽  
Commercial Glass ◽  
Carbon Fiber Reinforced ◽  
Reinforced Thermoplastics

Face guards (FGs) are protectors that allow for the rapid and safe return of athletes who are to play after sustaining traumatic facial injuries and orbital fractures. Current FGs require significant thickness to achieve sufficient shock absorption abilities. However, their weight and thickness render the FGs uncomfortable and reduce the field of vision of the athlete, thus hindering their performance. Therefore, thin and lightweight FGs are required. We fabricated FGs using commercial glass fiber-reinforced thermoplastic (GFRTP) and carbon fiber-reinforced thermoplastic (CFRTP) resins to achieve these requirements and investigated their shock absorption abilities through impact testing. The results showed that an FG composed of CFRTP is thinner and lighter than a conventional FG and has sufficient shock absorption ability. The fabrication method of an FG comprising CFRTP is similar to the conventional method. FGs composed of commercial FRTPs exhibit adequate shock absorption abilities and are thinner and lower in weight as compared to conventional FGs.

scholarly journals Evaluation of Microstructure and Impact Toughness of Shielded Metal Arc Dissimilar Weldments of High Strength Low Alloy Steel and Austenitic Stainless Steel

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Misbahu A Hayatu ◽  
Emmanuel T Dauda ◽  
Ola Aponbiede ◽  
Kamilu A Bello ◽  
Umma Abdullahi
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Toughness ◽  
Impact Energy ◽  
High Strength ◽  
Impact Testing ◽  
Welding Parameters ◽  
Dissimilar Weld ◽  
Weld Joints ◽  
The Impact

There is a growing interest for novel materials of dissimilar metals due to higher requirements needed for some critical engineering applications. In this research, different dissimilar weld joints of high strength low alloy (HSLA) and 316 austenitic stainless steel grades were successfully produced using shielded metal arc welding (SMAW) process with 316L-16 and E7018 electrodes. Five variations of welding currents were employed within the specified range of each electrode. Other welding parameters such as heat inputs, welding speeds, weld sizes, arc voltages and time of welding were also varied. Specimens for different weld joint samples were subjected to microstructural studies using optical and scanning electron microscopes. The impact toughness test was also conducted on the samples using Izod impact testing machine. The analysis of the weld microstructures indicated the presence of type A and AF solidification patterns of austenitic stainless steels. The results further showed that the weld joints consolidated with E7018 electrode presented comparatively superior impact energy to the weldments fabricated by 316L-16 electrode. The optimum impact energy of E7018-weld joints (51J) was attained at higher welding heat inputs while that of 316L-16-weld joints (35J) was achieved at lower welding heat inputs, which are necessary requirements for the two electrodes used in the experiment. Hence, the dissimilar weld joints investigated could meet requirement for engineering application in offshore and other critical environments.Keywords—Dissimilar metal weld, heat input, impact toughness, microstructures

scholarly journals Finite Element Analysis of Shock Absorption of Porous Soles Established by Grasshopper and UG Secondary Development

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xiaoying Liu ◽  
Yong Yue ◽  
Xuyang Wu ◽  
Yanhua Hao ◽  
Yong Lu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Porous Structure ◽  
Secondary Development ◽  
Shock Absorption ◽  
Absorption Effect ◽  
Element Analysis ◽  
Computer Aided ◽  
Peak Plantar Pressure ◽  
Shoe Soles

On the basis of computer aided modeling technology, this paper proposes a porous structure modeling method based on Grasshopper visual programming language and Unigraphics NX (UG) secondary development platform. The finite element model of the foot was established, and then models of shoe soles with four basic porous structures of cross, diamond, star, and x were established. Each structure was set with a cylindrical radius of 1, 2, and 3 mm, and a total of 12 porous structure sole models were established. The shock absorption effect of the sole on the foot was evaluated by the deformation of the sole, the peak plantar pressure, and the peak stress of metatarsal bones. It is found that the maximum value of the sole deformation of the diamond porous sole is 4.725 mm, the peak plantar pressure is 105.1 Pa, and the first and second metatarsal peak pressures are 2.230 MPa and 3.407 MPa, which have the best shock absorption effect. It shows that the porous structure plays an important role in the cushioning of the sole. The biomechanical effects of porous soles on feet are studied by computer-aided technology and finite element analysis. This study provides a new research method for the cushioning design of shoe soles and has important reference value for the design of footwear.

Influence of Cooling Time t8/5 on Impact Toughness of P460NL1 Steel Welded Joints

2020 ◽  
Vol 1157 ◽  
pp. 154-160
Author(s):  
Simon A. Sedmak ◽  
Mihajlo Aranđelović ◽  
Radomir Jovicic ◽  
Dorin Radu ◽  
Ivica Čamagić
Keyword(s):  
Crack Initiation ◽  
Crack Propagation ◽  
Impact Energy ◽  
Welded Joint ◽  
Welding Process ◽  
Impact Testing ◽  
Cooling Time ◽  
Initiation And Propagation ◽  
Higher Temperature ◽  
Total Impact

The results of impact testing of welded joint specimens taken from a welded plate made of P460NL1 steel are presented in this paper, and analysed with regards to the cooling time t8/5, that was previously calculated. The aim was to determine how the cooling times that were measured, some of which were below the minimum required values, affected the toughness, in terms of total impact energy and its components, crack initiation and crack propagation energy. In addition, this analysis included the effects of temperatures measured at the opposite ends of the plate during the welding process, since this had also affected the cooling times for each welding pass. After observing the differences in total, crack initiation and propagation energy between the tested specimens taken from different parts of the welded plate, it was determined that the specimens from the part where the higher temperatures were measured had shown better, more uniform results, whereas the average total impact energy for specimens from both groups were very similar. It was also noticed that the ratio of crack propagation to crack initiation was more favourable (greater) in the case of specimens from the second group (with higher temperature), as the values of crack initiation energy decreased slightly and the crack propagation energy increased.

Effect of Testing Conditions on Performance and Durability of Stabilisers in Plastics

2003 ◽  
Vol 11 (2) ◽  
pp. 81-90 ◽  
Author(s):  
J. Pospíšil ◽  
Z. Horák ◽  
J. Pilař ◽  
S. Nešpurek ◽  
N. C. Billingham ◽  
...  
Keyword(s):  
Thermal Aging ◽  
Material Properties ◽  
Activation Energies ◽  
Physical Processes ◽  
Factors Affecting ◽  
Testing Conditions ◽  
Testing Method ◽  
Principal Factors ◽  
The Individual ◽  
Accelerated Thermal Aging

The accelerated thermal aging and weathering of stabilised plastics provides information on stabiliser efficiency and polymer durability more quickly than natural testing. This allows the monitoring of the material properties of plastics in the foreseen application environment and the development of new stabilisation formulations. The harshness of the testing method affects the individual processes involved regarding their activation energies and mechanisms, the physical relations in the polymer – stabiliser system, and the chemical and physical processes accounting for the consumption of stabilisers. The principal factors affecting any comparison of accelerated results with natural testing are outlined.

scholarly journals Study on Integrity Diagnosis of Damaged RC Pier by using Impact Testing Method

1998 ◽  
Vol 1 ◽  
pp. 161-166
Author(s):  
Tomoyuki YAMAZAKI ◽  
Shuichi MIKAMI ◽  
Toshiyuki OSHIMA ◽  
Kazunori KUBOTA
Keyword(s):  
Impact Testing ◽  
Testing Method

Construction principle of NES shock absorber and its application in frame structure

2019 ◽  
Vol 16 (4) ◽  
pp. 625-645
Author(s):  
Haixu Yang ◽  
Feng Zhu ◽  
Haibiao Wang ◽  
Liang Yu ◽  
Ming Shi
Keyword(s):  
Finite Element ◽  
Seismic Response ◽  
Seismic Performance ◽  
Shock Absorber ◽  
Frame Structure ◽  
Shock Absorption ◽  
Absorption Effect ◽  
Content Type ◽  
Main Structure ◽  
Nonlinear Shock

Purpose The purpose of this paper is to describe the structure of nonlinear dampers and the dynamic equations, and nonlinear realization principles and optimize the parameters of nonlinear dampers. Using the finite element method to analyze the seismic performance of the frame structure with shock absorber. Design/methodology/approach The nonlinear shock absorber was installed in a six-storey reinforced concrete frame structure to study its seismic performance. The main structure was designed according to the eight degree seismic fortification intensity, and the time history dynamic analysis was carried out by Abaqus finite element software. EL-Centro, Taft and Wenchuan seismic record were selected to analyze the seismic response of the structure under different magnitudes and different acceleration peaks. Findings Through the principle study and parameter analysis of the nonlinear shock absorber, combined with the finite element simulation results, the shock absorption performance and shock absorption effect of the nonlinear energy sink (NES) nonlinear shock absorber are given as follows: first, the damping of the NES shock absorber is satisfied, and the linear spring stiffness and nonlinear stiffness of the shock absorber are based on the relationship k1=kn×kl2, so that the spring design length is fixed, and the linear stiffness of the shock absorber can be obtained. The nonlinear shock absorber has the characteristics of high rigidity and frequency bandwidth, so that the frequency is infinitely close to the frequency of the main structure, and when the mass of the shock absorber satisfies between 0.056 and 1, a good shock absorption effect can be obtained, and the reinforced concrete with the shock absorber is obtained. The frame structure can effectively reduce the seismic response, increase the natural vibration period of the structure and reduce the damage loss of the structure. Second, the spacer and each additional shock absorber have a small difference in shock absorption effect. After the shock absorber parameters are accurately calculated, the number of installations does not affect the shock absorption effect of the structure. Therefore, the shock absorber is properly constructed and accurately calculated. Parameters can reduce costs. Originality/value New shock absorbers reduce earthquake-induced damage to buildings.

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