Design and Fabrication a Lightweight Spring Made of Natural Rubber for a Motorcycle’s Shock Absorber

Author(s):  
V. Mann ◽  
C. Dechwayukul ◽  
W. Thongruang ◽  
S. Srewaradachpisal ◽  
P. Kaewpradit ◽  
...  

This research aims to design and fabricate a spring made of natural rubber for a lightweight motorcycle’s shock absorber. This study is carried out in four main steps. First, a stiffness property of a steel coil spring and a damping property of a commercial shock absorber were tested using an Instron® material testing machine and a test rig. Second, six different types of rubber compounds (A-1, A-2, A-3, B-1, B-2, and B-3) were formulated and the best compound was selected to use for a rubber spring. Third, the rubber spring was designed and analyzed using the finite element method to investigate the best model. Finally, a prototype of the rubber spring was fabricated and tested. The steel coil spring was replaced by the rubber spring and tested for its damping property within a real shock absorber. The results of the prototype testing showed that the weight of the rubber spring was lower than the steel coil spring about 48%. The stiffness property of the rubber spring was higher than the steel coil spring around 43% and the damping property of the shock absorber using rubber spring was higher than the damping property of the shock absorber using steel coil spring about 6%.  The rubber spring provided more advantages than the steel coil spring for its good corrosion resistance, lightweight, and ease of maintenance. However, the implementation of the rubber spring in the real motorcycle and its fatigue life should be studied in the next future.

2021 ◽  
Vol 6 (1) ◽  
pp. 32
Author(s):  
Nanang Ali Sutisna

<em>Universal Testing Machine or UTM (Universal Testing Machine) is a material testing machine that has more than one type of material testing. The purpose of this research is to design and analyze the strength of the UTM construction for tensile and bending tests. This machine uses a hydraulic jack as a power source to provide the required load. The design is limited to a load of 1.4 tons while the maximum construction load is 5 tons according to the hydraulic jack capacity. The method used in this study begins with a design using CAD and then analyzed with the finite element method. From the results of the analysis and evaluation, the designed tool can be used safely in accordance with the specifications used. The results showed that from the experimental results on the tensile and bending test specimens, both tests were successfully carried out. The tensile test was carried out with SUS 304 and SS400 with different thicknesses with dimensions according to ASTM E8 standards, while the bending test was carried out on ASTM A36 material with a size of 200 x 40 x 6 mm. After the test is carried out, the construction of the machine is checked for possible defects due to the test, namely the upper and lower clamps, punches and dies, and the engine frame. As a conclusion, after testing, it turns out that no damage or defects were found in all the parts examined</em>


2019 ◽  
Vol 48 (3) ◽  
pp. 224-248
Author(s):  
Pablo N. Zitelli ◽  
Gabriel N. Curtosi ◽  
Jorge Kuster

ABSTRACT Tire engineers are interested in predicting rolling resistance using tools such as numerical simulation and tests. When a car is driven along, its tires are subjected to repeated deformation, leading to energy dissipation as heat. Each point of a loaded tire is deformed as the tire completes a revolution. Most energy dissipation comes from the cyclic loading of the tire, which causes the rolling resistance in addition to the friction force in the contact patch between the tire and road. Rolling resistance mainly depends on the dissipation of viscoelastic energy of the rubber materials used to manufacture the tires. To obtain a good rolling resistance, the calculation method of the tire finite element model must take into account temperature changes. It is mandatory to calibrate all of the rubber compounds of the tire at different temperatures and strain frequencies. Linear viscoelasticity is used to model the materials properties and is found to be a suitable approach to tackle energy dissipation due to hysteresis for rolling resistance calculation.


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1153
Author(s):  
Franz Konstantin Fuss ◽  
Asliza Ahmad ◽  
Adin Ming Tan ◽  
Rizal Razman ◽  
Yehuda Weizman

Hard-shell thoracolumbar sacral orthoses (TLSOs) are used for treating idiopathic scoliosis, a deformation of the spine with a sideways curvature. The pressure required inside the TLSO for ideal corrective results remains unclear. Retrofitting TLSOs with commercially available pressure measurement systems is expensive and can only be performed in a laboratory. The aim of this study was to develop a cost-effective but accurate pressure sensor system for TLSOs. The sensor was built from a piezoresistive polymer, placed between two closed-cell foam liners, and evaluated with a material testing machine. Because foams are energy absorbers, the pressure-conductance curve was affected by hysteresis. The sensor was calibrated on a force plate with the transitions from loading to unloading used to establish the calibration curve. The root mean square error was 12% on average within the required pressure range of 0.01–0.13 MPa. The sensor reacted to the changing pressure during breathing and different activities when tested underneath a chest belt at different tensions. The peak pressure reached 0.135 MPa. The sensor was further tested inside the scoliosis brace during different activities. The measured pressure was 0.014–0.124 MPa. The results from this study enable cheaper and mobile systems to be used for clinical studies on the comfort and pressure of braces during daily activities.


1998 ◽  
Vol 37 (4) ◽  
pp. 469-481 ◽  
Author(s):  
HANAFI ISMAIL ◽  
U. S. ISHIAKU ◽  
A. R. ARINAB ◽  
Z. A. MOHD ISHAK

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