Laminated neoprene pad Experiment

Welcome to our website News on Crunch, as we know there are various applications of Laminated Neoprene pad under construction of bridges due to their elastomeric tendency. So, let's perform an experiment and get to know more about this:

Objective(s) for Laminated Neoprene Pad

• To determine the equivalent modulus of elasticity of a laminated neoprene pad under axial compression load by plotting a stress-strain curve based on the recorded data.

Materials and Resources

1. Measured dimensions of laminated neoprene pad, L × B × t = 250 × 200 × 44 mm 
2. Rubber layer: 8 mm thick 3 Nos.
3. Steel plates: 3 mm thick 4 Nos.
4. Top and bottom rubber cover: 4 mm thick 2 Nos.
5. Side cover rubber: 6 mm thick (all four sides)
6. Steel plate area: 238 × 188 mm = 44744 mm2
7. Shore-A hardness of the specimen: 70 (approximately )
8. Modulus of elasticity of steel = 205 GPa

Code(s)

Code 1 : Description(write it in Octave or Matlab)

clc 

clear

data = csvread('your csv file name(eg: neoprene_compression.csv)');

u1 = 35.5178 - data(:,2);

u2 = 33.2294 - data(:,3);

u3 = 28.6471 - data(:,4);

u4 = 29.9547 - data(:,5);

load = data(:,1);

stress = load / 4.4744;

u = (u1 + u2 + u3 + u4)/4;

strain = u / 88;

hf = figure ();

scatter(strain,stress);

xlabel('strain')

ylabel('stress')

saveas (hf, "figure1.png");

Results (stress vs strain for Laminated Neoprene Pad)

Figure : Stress (MPa) vs Strain(mm/mm) for a Laminated Neoprene Pad

Answers

Calculate stress vs strain data, Apparent E and Equivalent E.

• The values of Stress and Strain for the laminated Neoprene pad are given in the graph on y-axis and x-axis respectively. 
• Apparent E = (20 - 10) / (0.079499 - 0.058397) = 473.889 MPa 
• Equivalent E = 44 / ((12 / 205) + (32 / 473.889) MPa = 651.033 MPa

My Own Observations and Comments

1. The laminated elastomeric bearing pad has fine elasticity which can adapt the rotation of beam end and also it has great shearing deformation capacity which can satisfy the horizontal displacement of the superstructure. It has sufficient vertical rigidity which can reliably transfer the concentrated down-loads and impact loads of the superstructure to both ends of the pier.
3. Some applications in our life are like, Bridges with small displacements and short spans, Load bearings of building structures, Flyovers, etc. In addition to being used in bridges, it also can be used for hydraulic engineering and earthquake resistant facilities.
4. The laminated rubber bearing pads can reduce the pier vibration and accommodate the horizontal movement on the bridge span structure caused by the temperature changing and thermal expansion