1110. Measurement of stresses in the vibrating elements of a printing device.

In this paper measurement of stresses in vibrating elements of the printing device using photo-elastic techniques is investigated. Numerical procedure is applied to obtain data which is needed for the interpretation of experimental results of time averaged photoelasticity when sinusoidal vibrations according to the eigenmode of the structure in the problem of plane stress take place. The results obtained from this numerical procedure correspond with the results obtained analytically earlier. The numerical procedure is also applied to obtain data which is needed for interpretation of experimental results when the structure is slowly loaded from the status of equilibrium by linearly increasing the load till its final value. Experimental measurements of stresses in polymeric films have been performed. Qualitative investigations of stresses of samples of LDPE films were performed by taking into account the level of stresses in unloaded samples as well as in samples experiencing tensile loading. Samples of LDPE films having various characteristics were analyzed. In order to obtain photoelastic images representing stress distributions in the investigated polymeric films the experimental setup was developed. In the loaded samples of the investigated films of LDPE type higher order photoelastic fringes are observed. They enable to interpret stress distributions in the films. This is especially important in the process of operation of the printing device. The obtained results are used in the process of measurements of stresses in the elements of a printing device. [ABSTRACT FROM AUTHOR]