Lack of Fusion Inspection

In this tutorial, you will learn how to simulate a Lack of Fusion (LOF) Inspection using BeamTool and the OnScale plugin. Let's get started by opening up BeamTool 9!

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Overview

Lack of fusion is one of the more serious defects that occur in welds. Lack of fusion is due to poor welding resulting in the weld metal not being fused with the surfaces of the parent metal. It is therefore very important to inspect welded joints using NDT methods like the one we will simulate today.

Section 1 - Piece

We are going to use the default plate piece for this tutorial, but it is easy to change these parameters by simply clicking on the Piece icon in the toolbar. 

Section 2 - Probe

The only probes currently supported by the OnScale plugin is Phased Array. Add a phased array probe by selecting the Probe icon in the toolbar.

To set the frequency of the probe, select the Probe Configuration button in the PA Probe window.

In the PA Probe Configuration window, set Frequency to 5 MHz.

Section 3 - Weld Defect

To add the defect in the weld, select the Draw Piece Polygon icon.

To place the defect on the weld, click on the weld to create the first point, drag your mouse and click to place the second point. Drag again and click to create the third point. Select Esc to complete the polygon. Don't worry where you are placing the defect just now, we are going to move the location to the weld surface.

To do this double click the polygon and in Construction Aids, set the properties to the following.

Section 4 - Beamset

We are going to use a sectorial beamset for this inspection. Add this by selecting the Sectorial Beamset Configuration button.

When simulating a beamset a simulation time must be chosen. The longer the simulation time the more core hours the simulation will take. The simulation time can be optimised using the Time From Elements crop value for the beamset. The simulation time needs to be twice what is in the crop value (to account for the sound returning to the transducer).

In the Sectorial Beamset Configuration window, set the Crop Mode to Time From Elements.

Then set Crop Time to 29.89 us, Start Element to 15 and Num Beams to 26.

The final inspection set up should like this.

Section 5 - Run

To run the simulation on the cloud, select Tools > onscale. 

The first thing you must do is login.

Don't have an OnScale Account? Find out how to get one here.

Once you are logged in, you must set up the final simulation parameters in the General tab.

To submit a job, go to the Submit tab, select the beamset to use and select Run Simulation.

Section 6 - Download

Once the simulation is finished, it will appear in the Download tab. To download the results simple select the Download button.

Section 7 - Import Results

The downloaded ONSCALE file can be imported into BeamTool to view the inspection B-scan. Do this by selecting the beamset in the PA probe window and selecting the cog > Import Data.

To increase the Gain of the B-scan, select the eye icon and change the value of the gain until the defect in the weld is clear. To show the beam folded, select the Folded button.