Shakir Khan [000645764)BEng (Hons) Mechanical Engineering 2013/2014

Supervisor : Dr Kaushika Hettiaratchi

Response of Systems with Integrated Fluid and Solid Dampers

• Damping is one of the many different procedures that have been introduced to the word for allowing an object to achieve its greater performance when it is subjected to, wind storm, earthquake or other type of transient shock and vibration disturbance. There are many type of dampers exist up to day to use for vibration disturbance, but mostly used are solid damper and fluid damper.

• Here, an experiment is conducted to test a principle on response of integrated fluid/solid dampers with reference to fluid dampers. The experiment will be conducted using a force method analysis. An initial Investigation will be required to be undertaken to determine which materials and geometries are suitable this type of application.

Background Information

Fluid damper with spring

F – ΣresistanceSolid damper

AimsComparing Fluid and Integrate Solid/Fluid Damper

Objectives

• Designed a test rig to perform the experimental studies for testing fluid and integrated fluid-solid damper• Compared the response of the integrated fluid-solid damper relative to

fluid damper• Examined the behaviour of solid material (sponge) when soaked in oil

(fluid)• Presented analytical discussion of the designed system

Important Factors

Stiffness of spring, voidage of specimen. Displacement, time, temperature and force. Velocity and force. Kinetic energy, potential energy.

• Building of the test facility and material selection• Fluid(oil used for experiment) and solid material(Sponge)

selection• Experimental work and data acquisition • Data analysis and modelling

Project Strategy

Design and Building of Test Facility

Test facility was designed using Solid Works. Test facility was manufactured at the laboratory. CES material database was used for material selection. The specimen (Sponge) was bought at the local shop.

Experimental Work and Data Acquisition

The displacement and time results were normalised to velocity. Velocity and force

5 10 15 20 25 30 35 40 45 500

1

2

3

4

5

6

7

8

Spring, Dashpot & Yellow Specimen

Hydraulic OilGear OilMotor Oil2-Stroke Oil

Force (N)

Velo

city

10-3

5 10 15 20 25 30 35 40 45 500

10

20

30

40

50

60

70

80

90

100

Dashpot and Spring

Hydraulic OilLinear (Hydraulic Oil)Gear OilLinear (Gear Oil)Motor OilLinear (Motor Oil)2-Stroke OilLinear (2-Stroke Oil)

Force (N)

Velo

city

10-3

(m/s

)

Changes in Fluid PropertyThe fluids property changes when force applied to integrated damper via piston

Change in properties for hydraulic oil

Conclusions

Fluid dampers convert kinetic energy to heat energy, while integrated dampers convert kinetic energy to heat and strain energy.

Change in density of the oil is directly proportional to work done on the piston

The response of a integrated fluid/solid dampers is a function of temperature, density of fluid, viscosity of fluid and voidage of specimen.

The loading velocity-force response of fluid dampers is linear while the loading velocity-force response of integrated fluid/solid dampers is non-linear (polynomial).

Recommendation for Future Work

Specimen and oil behaviour Hysteresis loss on integrated dampers. Rheological behavior of Specimen (Sponge)

Rheological Behavior of Specimen

Reference

Elliott, J.; Windle, A.; Hobdell, J.; Eeckhaut, G.; Oldman, R.; Ludwig, W.; Boller, E; Cloetens, P.; Baruchel, J., Yannas, L., 2005. Linear Viscoelastic Behavior,: Taylor1, D. 2014. FLUID VISCOUS DAMPERS USED FOR SEISMIC ENERGY DISSIPATION IN STRUCTURES. Harris, W., 2011. Dampers: Shock Absorbers.