The Thick Wall Cylinder FortiTestX-41 is a structural mechanics laboratory unit for investigating the triaxial stress and strain state in a thick-walled cylinder under internal pressure. This thick wall cylinder features a two-part aluminium cylinder (300 mm length, 140 mm diameter, 50 mm wall thickness) with a maximum operating pressure of 7 N/mm² (70 bar). Ten half-bridge strain gauges at 350 Ohm are positioned at multiple radial locations in the eccentric groove and on the cylinder surfaces, covering radial, hoop, and axial strain measurement. A hydraulic cylinder with spindle generates pressure, displayed on a 0 to 100 bar gauge, with optional Windows-based Software FX-41 supporting Mohr's Circle analysis and principal stress determination.

Thick Wall Cylinder FortiTestX-41, Technical Specifications
| Parameter | Detail |
|---|---|
| Model Reference | FortiTestX-41 |
| Category | Strength of Materials and Structures |
| Cylinder Material | Aluminium |
| Cylinder Length | 300 mm |
| Cylinder Diameter | 140 mm |
| Wall Thickness | 50 mm |
| Maximum Internal Pressure | 7 N/mm² (70 bar) |
| Pressure Gauge Range | 0 to 100 bar |
| Pressure Generation | Hydraulic cylinder with spindle |
| Hydraulic System | Hermetically sealed, oil-filled, maintenance-free |
| Cylinder Construction | Two-part with eccentric flat groove |
| Strain Gauge Quantity | 10 |
| Strain Gauge Configuration | Half-bridges, 350 Ohm |
| Gauge Factor | 2.00 +/- 1% |
| Strain Gauge Positions | Various radial positions in groove, inner and outer cylinder surfaces |
| Amplifier Supply Voltage | 10 V |
| Optional Software | Software FX-41 (Windows-based) |
Technical Data
Aluminium Cylinder
| Parameter | Value |
|---|---|
| Length | 300 mm |
| Diameter | 140 mm |
| Wall Thickness | 50 mm |
| Maximum Internal Pressure | 7 N/mm² (70 bar) |
Strain Gauge System
| Parameter | Value |
|---|---|
| Number of Strain Gauges | 10 |
| Configuration | Half-bridges |
| Resistance | 350 Ohm |
| Gauge Factor | 2.00 +/- 1% |
| Measurement Positions | Various radial positions in groove, inner surface, outer surface |
| Amplifier Supply Voltage | 10 V |
| Measurement Coverage | Radial, hoop, and axial strain positions |
Pressure System
| Parameter | Value |
|---|---|
| Pressure Generation | Hydraulic cylinder with spindle |
| Maximum Internal Pressure | 7 N/mm² (70 bar) |
| Pressure Gauge Range | 0 to 100 bar |
| Hydraulic Fluid | Oil |
| System Type | Hermetically sealed, maintenance-free |
Key Features
Experiments
Construction and Design
The Thick Wall Cylinder FortiTestX-41 is built around a two-part aluminium cylinder measuring 300 mm in length, 140 mm in diameter, and 50 mm in wall thickness. An eccentric flat groove is machined at the joint between the two cylinder sections, providing access for strain gauge bonding at multiple radial positions within the wall. Additional strain gauges are mounted on both the inner and outer cylinder surfaces to complete the measurement coverage. Ten strain gauges in total are configured as half-bridges at 350 Ohm with a gauge factor of 2.00 +/- 1%, covering radial, hoop, and axial strain positions. Internal pressure is generated by a hydraulic cylinder and spindle, with a maximum operating pressure of 7 N/mm² (70 bar). A pressure gauge graduated to 100 bar displays the applied pressure. The cylinder is filled with oil and sealed hermetically, requiring no maintenance. The measuring amplifier operating at 10 V supply reads strain signals directly from all gauges. This thick wall cylinder interfaces with optional Windows-based Software FX-29 for data loading, visual evaluation, and Mohr's Circle analysis of the triaxial stress condition.
Software
Software FX-41 (Optional): Windows-based software with a universal strain gauge amplifier interface for data logging, graphical strain display, and Mohr's Circle visualisation of the triaxial stress state. Compatible with any Windows operating system.
Scope of Delivery
Q1: What is the maximum internal pressure the Thick Wall Cylinder FortiTestX-41 can withstand?
The maximum internal pressure is 7 N/mm² (70 bar), generated by the hydraulic cylinder and spindle arrangement.
Q2: How does this thick wall cylinder differ from a thin-walled cylinder apparatus?
In a thick-walled cylinder, stress distribution across the wall thickness is non-uniform and triaxial, involving radial, circumferential, and axial stresses simultaneously. The 50 mm wall thickness and groove-mounted internal strain gauges on this unit allow direct investigation of this stress distribution, which is not possible with thin-wall apparatus.
Q3: How many strain gauges are used and where are they positioned?
Ten strain gauges in half-bridge configuration are bonded at various radial positions within the eccentric groove between the two cylinder sections, as well as on the inner and outer surfaces of the cylinder.
Q4: Is Mohr's Circle analysis supported?
Yes. Optional Software FX-41 provides graphical Mohr's Circle representation of the triaxial stress condition for visual evaluation and principal stress determination.
Q5: Does the hydraulic system require maintenance?
No. The hydraulic system is hermetically sealed and oil-filled, requiring no maintenance.