True Triaxial Test System ©

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The integrated True-Triaxial Test Cell Platen and Seal System is designed for large strain deformation (4% to 8%) and to date has been built to accommodate 80mm cube and 80x160mm prism samples. Designs have been produced to a accommodate a 240mm cube

The unique three element Seal System compensates for the large movements whilst maintaining a gas tight seal between the TTSCP Test Rig containment pressure vessel and the cube/prism under testing.

1. Axial "Telescopic" Anti-Extrusion Rods in Engineering Plastic

2. Soft Deformable rubber - 12 Off 3d Mitred Strips

3. Flexible Rubber Integrally Bonded To Stress Support Platen

The platens of the TTT cell are made of two elements:

1. Stress support platens made in high tensile stainless steel (17/4-PH Condition H1150) to spread the applied load by the 3D hydraulic jack system)

2. Interposing sample platens made in aluminium alloy (6082 -T6) for Modulus compliance and for interchange-ability in case of damage during the testing

The six platens of the test cell are held together by precision machined "L" elements using ISO 12.9 M5 button head socket head fasteners which can be backed out during 3D straining.

The X2, Y2 and Z2 platens were also fitted with sliding spherically seated plates made in hard tool steel. This was incorporated to compensate for a potential skewing of the loading by the original three-jacks on three faces (X1, Y1 and Z1) only of the test specimens. The spherical seats were incorporated to allow tilting of the X1/X2 and Y1/Y2 platen sets due to the pressure drop between Z1 and Z2 platens during permeability determinations.

Auxiliary stool with Z2 platen mounted.

Enlarged view of SE2/SE1 strip insertion in X2/Y2 edge of test cell.

All horizontal and vertical SE2/SE1 strips installed.

Insertion of 80mm gauge cube.

Gauge cube inserted

View of X2/Y2/Z2 SE1 3D mitred corner at zero strain in all three orthogonal directions.

Pushing / rotating helical sliding bush (item 3) to make correct 3D mitred joint at X2/Y1/Z1 corner.

Z1 platen opened.

Comparison of Strain of Tested Cube to Plastic Gauge Cube.

Strained cube resting on Z2 and X2 platens.

Plan view of tested cube beside 80mm plastic gauge cube.

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Isometric View

Illustration of large strain on tested cube

ErgoTech
Unit 3 Cae Ffwt Business Park Glan Conwy Conwy
LL28 5SP UK

This drawing is copyright (c) and the associated procedure is the property of ErgoTech. It is issued confidentially to parties interested in acquiring the process and to authorised/licensed clients using it. The drawing is not to be reproduced or circulated by any parties without the written consent of ErgoTech which will not be unduly withheld. The drawing must not be mounted on any display boards or reproduced in reports without the written consent of ErgoTech. When permission is granted the reproduction must be identical to the original and the ownership of the drawing and the process embodied acknowledged to ErgoTech by displaying "ErgoTech (c)"

ErgoTech
Tel. (44) (0)1492 592684
Fax. (44) (0)1492 592685