Facilities

Facilities

The research group have a range of testing machines and equipment at their disposal both in the timber research laboratory and from other facilities based in NUI, Galway. These facilities include both experimental and computational facilities. A brief description of the most important items are given below:

Experimental Facilities

Dartec 500 kN Servo Hydraulic Testing Machine

This machine is the primary testing machine in the laboratory and is associated with the following features:

• 500kN load capacity.
• An adjustable cross-head which gives ram travel of up to 3.5m
• Test bed length of 7m.
• Interchangeable plates and loading frames.
• Capabilities for both load and displacement control tests.
• Easy manipulation so that tension testing, compression testing and shear testing can be carried out.
• Three and four-point bending test capability.
• Dartec 9500 Controller.
• Static and dynamic test capability.

Although this machine was purchased primarily for the timber laboratory it is in regular use by researchers and undergraduate students in other sections within the department.

Dartec 250kN Servo Hydraulic Testing Machine:

The Dartec 250kN has the following features:

• 250kN load capacity.
• An adjustable cross-head which provides ram travel of up to 1.5m.
• Interchangeable plates and loading frames.
• Capabilities for both load and displacement control tests.
• Easy manipulation so that tension testing, compression testing and shear testing can be carried out.
• Three and four-point bending test capability.
• Computerised data acquisition.

Timber Stress Grading Machine (Cook-Bolinder):

The timber laboratory boasts a Cook Bolinder stress grading machine. Mechanical strength grading is essential in the selection of quality timber for the construction industry and is fundamental in structural timber design.

Mechanical grading is a much faster process than visual grading and is carried out by testing a property or properties non-destructively. The procedure certifies that the timber piece is associated with the desired strength and stiffness characteristics for the application for which it is required.

The current European standard, EN 14081-4 (2009) specifies that a pre-set deflection based on the species, board thickness and width, must be input into the settings of the grading machine. The load required to obtain the pre-set deflection is recorded for both sides of the board and the mean value for each location is determined. The grading procedure involves passing the board between the load cell and support rollers such that bending is induced about its minor axis, turning it over and passing it through again.

The machine has the features as listed below:

• Computerised rejection of boards which fail to obtain the required structural grade. 
• Computerised data acquisition.
• Test span of 900mm.
• Third point (centre point) loading.
• Flatwise bending stiffness readings at 100mm intervals. 
• Computerised automatic rejection of boards that do not obtain the required structural grade. 
• Infeed and outfeed roller tables of 3.5m length.

MTG Acoustic Timber Grader:

The MTG acoustic timber grader is a lightweight measurement device that uses an acoustic method to predict the strength class of timber boards by the dynamic Modulus of Elasticity and density.

The machine has the features as listed below:

• Computer software “Timber Grader” for storage and reporting of measurement data.
• Integrated mass balance for accurate density measurement.
• Handheld device complete with Bluetooth communication adaptor.
• Calibration set.

Glue Laminating Timber Press: 

The press was specially designed and fabricated so that glued laminated timber beams can be designed and manufactured in the laboratory.

• Capability to produce 4.6 m long beams.
• Lay-up design based on Cook Bolinder material data.
• 13.8 m² preparation area complete with fume hood for adhesive application.
• Flatwise clamping pressure applied through two RHS steel sections in accordance with EN 14080 (2013).
• Edgewise clamping pressure applied to ensure no warping or twisting of individual laminations.

Conditioning Chambers: 

The Timber Engineering Laboratory has two climate chambers. The first of these chambers is a constant climate chamber where temperature is maintained at a temperature of 20°C ± 2°C and relative humidity of 65% ± 5% in accordance with EN 408. In general, these conditions result in a nominal 12% moisture content for softwoods. The second of these chambers is a variable climate chamber used to examine various timber elements at different moisture content.

Features of these conditioning chambers include: 

Constant climate chamber

• Constant temperature and relative humidity controlled environment.
• Data acquisition of temperature and relative humidity.
• Area of 37.6 m²
• Durable racking to store members up to 7 m long.
• Easily accessible for deliveries.

Variable climate chamber

• Temperature control ranging from 10°C to 40°C with an accuracy of ± 2°C.
• Relative humidity control ranging from 10% to 90% with an accuracy of ± 5%.
• Data acquisition of temperature and relative humidity.
• Area of 7.4 m²

Computational Facilities

‌The computation facilities in the department comprise of two components primarily. 

• State of the art hardware and software for data acquisition and for advanced engineering analysis.
• Finite element software including ANSYS and ABAQUS. 

Finite element modelling of timber and engineered wood components requires particular expertise. Timber is a complex material to numerically model because of the anisotropy behaviour it exhibits as well as the variability that exists in the material as a result of the high number of inhomogeneities that are randomly present. Furthermore, it is a heterogeneous material and problems are further complicated by its inherent nonlinear characteristics. Finite element analysis is a particularly useful tool for predicting the structural behaviour and performance of timber and is therefore considered a significant factor in increasing safety during the structural design process.