Tensile-test rig for beam-configuration fillet-weld samples

What it does; the requirement it fulfills

This tensile-testing rig can by design repeatedly take the "brutal" abrupt release of stored elastic energy from break at maximum load, which the "beam-configuration fillet-weld sample test" inflicts.

While providing accurate determination of the tensile force in the sample fillet weld at that breakage.

The sample does not possess a concept of yielding : yielding behaviour; yield point; yield stress. The only significant event with increasing force on the weld is its abrupt breakage. Hence - the test method in measuring the maximum force attained at the moment of weld breakage measures the only tensile characteristic the fillet-weld sample has.

The goal attained

The beam-configuration fillet-weld sample test presents a previously unfamiliar vision, that complete fillet welds can be easily and economically tested to unrestricted sizes of fillet weld.

A further vision for the future is that this test could be developed into a dynamic-load / cyclic-load test for fatigue-resistance of fillet welds. There being no foreseeable fundamental impediment currently to that goal.

The test rig presented

This is it - picture of the test rig produced and found good in trial tests:

First and foremost - keep distant from the test sample as load is increasing !!!
The typical 2 metres or more length of the hydraulic hose pulled straight away from the breaking rig to the hydraulic hand-pump is a good start.
On breaking, the sample halves "leap" spectacularly. So you need to keep well clear. Well outside the envelope of space within which those ropes restrain the sample parts to stay.

Impression of the test completion event is given in following image, indicating


The ropes binding the sample and "frame beam" are safety-critical and are integral to the design of the test method.
They are vital for the safe application of the test.
They constrain the sample halves to remain within a small envelope of space on sample breakage.
The following detailed comment is impressed upon readers as being important to know already, or to skill-acquire to mentor-approved competence.

Other comment:

Interpreting the test data - obtained weld break force from rig piston-force

Technically - the objective of the test...
Deduce, from the hydraulic-cylinder piston-force at the moment sample broke, the tensile force on the weld at that moment. Which might then be used to deduce stress levels in the weld at that moment.

Weld-metal break-strength from the trial fillet-weld beam-test

This is an example "working" of the arithmetic process. One would hope in future for more exact and citable input data.

The hydraulic hand-pump and cylinder has no pressure gauge. However, the cylinder can be put in the "shop" press seen in Fillet welds tensile tested in beam test , where the force this hydraulic cylinder applies to the shop-press's ram causes a force reading on the press's gauge ( example - image ) . Giving an approximate semi-quantitative "calibration" of the force exerted on the pump handle to the piston force resulting. (!! - yes, this would normally seem "inexact methodology")

With no way to readily predict the deduced value of stress in the weld at break, there is no way to bias the estimate of force from pumping the handle in order to get a preferred value. I estimated 8Tonnes-force at the breaking for the sample seen in the picture.

Where the closeness of this 572MPa estimate of "G3Si1" breaking stress to the "expected" value of 560MPa is truly remarkable and surprising.

Evaluation of fillet-weld beam-test samples - see

This is an article on the beam-configuration fillet-weld tensile test, the testing method.
For interpretation and evaluation of fillet-weld performance, see the page on
Fillet-weld test evaluation .
Where this test outcome data is incorporated in the body of data and observations available - both my findings and established knowledge.

Recommendations for further work

A pressure-gauge on the pump giving a reading of the hydraulic pressure in the system would be very much recommended ;-)

(R. Smith, 24Jan2021, 26Jan2021 (edits, fractpg), 28Jan2021 (findings sep.), 28Jan2021 (break img.), 29Jan2021 (approx brk.str. retn), 31Jan2021 (break tensile, no yield, edits), 07Feb2021 (aname fwanalyse, F_w, pic cyl test), 08Feb2021 (pic cyl test), 11Feb2021 (dir img))