3/10/2024 0 Comments Tensile load on barThe right valve is used to apply the load and the left valve is used to release the load on the specimen. Extensometer must be removed before reaching the yield point. Note the extension at a convenient load increment. When the specimen is under load, slowly unclamp the locking handle. Load Application: Turn the right control valve slowly to open position to get the desired loading rate.Placing Extensometer: Fix the extensometer on the specimen and set the reading to zero.Once the specimen is placed, the jaws are locked. By operating the handle, lift the lower crosshead chuck up and grip firmly the lower part of the specimen. Adjust the load pointer to zero with the zero adjusting knobs. Open the right valve and close it after the lower table is slightly lifted. The left valve is kept in a fully closed position and the right valve in a normal open position. Placing the Specimen: The handle is operated such that the specimen firmly fits to the top base.From this, the range is calculated and this range is set in the UTM.Assuming working stress = 140N/mm²įactor of safety = 3.i.e Ultimate stress = 140x3 = 420N/mm².įrom the ultimate load, range to be used can be fixed. Range Calculation: A tensile stress value is assumed for which the maximum expected load capacity of the rod is calculated.The gauge length can be marked on the specimen by punching tool. The gauge length is calculated by the formula. Preparation of Specimen: Initially, the steel rod specimen is cleaned and gauge length is marked on it. Tension Test on Steel Rod Arrangement on UTM Percentage reduction in the area = (Change in length/Original Area)/100įig.2.Percentage elongation = (Change in length/Original Length)/100.Actual Breaking Stress = Breaking load/Neck Area.Nominal Breaking Stress = Breaking Load/Nominal Breaking Stress.Ultimate Stress = Ultimate Load/Original C/s Area.Yield Stress = Load at yield Point/Original C/s Area.Modulus of Elasticity, E = Stress/Strain.With the obtained values, the stress and strain are calculated and plotted in a graph. The load values at yield point, breaking point, and ultimate point are carefully noted. The specimen is subjected to constant tension load and the extension caused in the steel rod is noted against the load within the elastic limit. The range indicating dial is to be adjusted for the particular range selected. A pendulum dynamometer is fitted to measure and indicate the force coming on the specimen.Ī big size load indicating dial fitted with a glass cover is mounted at the side of the control panel. The load application is performed by the action of hydraulic pressure. When undergoing the tensile test, the upper and lower crossheads are used.Ĭontrol Panel: This unit facilitates the load application on the specimen. These crossheads are used depending on the type of load( tensile, compressive or shear) applied on the specimen. The loading unit consists of three crossheads, they are the upper head, middle head, and lower head. In the figure above, the equipment in the left is called as the loading unit. Fig.1.Universal Testing Machine (UTM) Loading unit: The loading of the specimen is conducted in the loading unit.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |