Student:	Uğur MAZLUM
Supervisor:	Prof. Dr. Sami KARADENİZ
Department:	Makina Mühendisliği
Institution:	Graduate School of Natural and Applied Sciences
University:	Karadeniz Technical University, Turkey

Title of the Thesis:	Experimental Investigation of the Stress Relaxation Behaviour
Level:	M.Sc.
Acceptance Date:	23/10/2008
Number of Pages:	109
Registration Number:	i1983

Summary:

In this thesis, the effects of the hardness on the stress relaxation behaviour of EPDM

rubber at the room temperature were experimentally investigated. EPDM rubber show

outstanding heat, ozone and weather resistance and has excellent electrical properties.

Therefore this rubber as an elastomer is an engineering material that has wide range of

applications in industry such as door and window seals, radiator, garden and heating hoses,

tubing, washers, belts, electrical insulation, roofing membrane and rubber mechanical

goods.

In the study, stress relaxation experiments were carried out for different loading

programs by using EPDM specimens having different hardness. As a result is found that it

is possible to make a stress relaxation estimate by using the data obtained for short

duration of stress relaxation experiments. In addition, for the loading programs that were

implemented in this study, it is shown that the stress relaxation curves obtained at different

stretch ratios may be represented by a single representative curve for EPDM specimens

having the same hardness.

Key Words: Rubber, EPDM Rubber, Hardness, Elastomers, Stress Relaxation, Stretch

Ratio