Structural Testing

Aries provides complete solutions to perform any of the following Test Categories:

Quasi-Static Test

In the quasi-static test, the specimen is subjected to a predefined history of loads or displacements. It is done at a reduced velocity compared to the expected velocity when subjected to, for example, an earthquake.

Pseudo-Dynamic Test

The pseudo-dynamic test is performed quasi-statically and provides a realistic simulation of the response of structures exposed to dynamic loadings.

In the PSD the equations of motion for a discrete parameter model of the test structure are solved on-line by numerical integration. Inertial and viscous damping forces are modelled analytically and the nonlinear structural restoring forces are measured experimentally. Hereby is automatically accounted for the hysteretic damping (this is the major source of energy dissipation) caused by in-elastic deformation and damage of the structural materials.

When the PSD test simulates a civil engineering structure exposed to an earthquake, the ground acceleration history of a real or a hypothetical earthquake is given as input to the computer. The horizontal displacements of the floors (the levels at which the mass of the building can be considered to be concentrated) are calculated for a small time step.

These displacements are applied to the structure by means of servo-controlled hydraulic actuators fixed to the reaction wall. Load-cells on the actuators measure the forces necessary to achieve the required deformation (the structural restoring forces) and these are used for the next time step of the calculation. The inertia forces are modelled. Thus, there is no need to perform the test in real time. Typically an earthquake lasting some ten seconds is simulated by a PSD test in an hour. The major advantage is the possibility to monitor closely the progression of damage in the structure and to pause at any moment for a detailed examination or to prevent complete collapse.

PSD tests are especially useful for confirmatory tests in full-scale where exact material and construction details can be reproduced, or when multi-point input loading is required.

Dynamic Test

In this test, the loads are applied in continuously on the structure. The dynamic test is used for fatigue or real time hybrid testing, as well as other applications as the Shaking Table, a device for shaking structural models or building components with a wide range of simulated ground motions, including reproductions of recorded earthquakes. The shaking table can be used to test the structural response to verify seismic performance.