Jan 042014
 

tensile test logoWithin destructive material testing the tensile test has a great importance as this test delivers the material characteristic values for the calculation of the strength of the shape. Further, it gives information on the deformability of a material.

Due to the fact that the results of tensile tests are of great importance for e.g. working and process tests it must be guaranteed that the test can be reproduced. Therefore, all possible parameters influencing the test, e.g. the type of the test equipment, the shape of the test piece, the execution of the tensile test must be avoided. This is possible by the compliance with the corresponding standards only.

Standards Refering to Tensile Test
DIN EN ISO 6892-1
Metallic Materials – Tensile Testing – Part 1:
Method of Test at room temperature
This standard applies to the tensile test for all metal-     lic material with and without fine strain measurement
DIN 50125
Tensile test specimens, directions for their preparation
EN 895 
Destructive test on welds in metallic materials
Transverse tensile test
EN 876
Destructive test on welds in metallic materials
Longitudinal tensile test

Execution of the Tensile Test
fracture
During the tensile test one or several of the characteristic values of strength and deformation described in the following will be determined. In doing so, a tensile test piece is elon-gated to fracture. The shapes of test pieces most frequently used are:

Tensile test piece form A – Round specimen with smooth cylinders heads for clamping
Tensile test piece form A
d0    diameter of specimen
d1    diameter of grip (» 1.2 d0)
L0    gauge length (L0 = 5 d0)
Lc    parallel length (Lc ³ L0 + d0)
Lt    total length
h    height of grip

Tensile test piece form B – Round specimen with screw thread
Tensile test piece form Bd0    diameter of specimen
d1    diameter of grip
L0    gauge length (L0 = 5 d0)Lc    parallel length (Lc ³ L0 + d0)
Lt    total length
h    height of grip

 

Tensile test piece form E – Flat specimen
Tensile test piece form Ea    thickness of specimen
b    width of specimen
B    width of grip (» 1.2 b + 3 mm)
h    height of grip (» 2 b + 10 mm)
L0    gauge length
Lc    parallel length (Lc ³ L0 + 1.5 ÖS0)
Lt    total length

Proportional test pieces according to DIN 50125 are tensile test pieces for which a fixed ratio between the initial measuring length L0 and the initial cross section S0 exists. For test pieces with a circular cross section L0 = 5 x d0 is valid in general. For test pieces with a prismatic cross section the initial measuring length
L0 = 5.65 • √S0
will result.
The tensile test on weld joints serves to determine the strength and deformation behaviour of weld joints transverse to the weld seam by means of determining the tensile strength, position and type of the crack.
The flat tensile test pieces are of such nature that the weld metal, the heat effected zone as well as the non-affected parent material are exposed to almost the same stresses. The shapes of the test piece according to EN 895 bzw. EN 876, respectively are listed below.

further test pieces

 

Alte articole asemanatoare
Terms and designations in connection with metal welding processes Back-step welding - Type of welding in which short pieces of the seam are welded against the main direction of welding in such ...
mai multe
Upon explaining the material stresses resulting from the action effects axial force N, shear force V and bending moment M. The peculiarities of stresses in welds and welded joints are ...
mai multe
A Time-Temperature-Transformation (TTT) diagram describes the decomposition of the austenite (after prior heating) and the structure generated by this. In order to set up a TTT diagram for continuous cooling rod-shaped ...
mai multe
The essential atomic structure consists of the nucleus together with the protons (positively charged) and the neutrons (electrically neutral) as well as the electrons (negatively charged). 1836 electrons together form the ...
mai multe
General introduction of welding technology.Definition of Terms
Basic of weld design – Stresses in Welded
Time-Temperature-Transformation Diagram
Built-up of the Elements – Structure and properties

 Leave a Reply

(required)

(required)

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>