Projects / Programmes
Glulam timber beams in natural environment
| Code |
Science |
Field |
Subfield |
| 2.01.03 |
Engineering sciences and technologies |
Civil engineering |
Constructions in civil engineering |
| Code |
Science |
Field |
| T230 |
Technological sciences |
Building construction |
glulam, changing environmental conditions, moisture diffusion, stress, strains, deflections
Researchers (10)
Organisations (2)
Abstract
In their function in natural environmental timber structures are exposed to random, wheatherdependent changes of relative humidity and temperature of ambient air. Especially interesting is the mechanoseroptive effect, expressed as the increase of deformations of loaded beams at the change of humidity, both in the case of sorption and desorption. This phenomenon is the subject of numerious theoretic and experimental researches which are most often limited to the study of amall specimens with sample loading.
In the framework of the proposed research project we intend to carry out a more detailed research of the behaviour of timber glulam beams of realistic dimensions in the natural environment, taking into account the irregular distribution of humidity in the beams, plastic deformations as well as direct influence of temperature on the deformations and indirect influence on the diffusional and mechanosorptive properties of glued timber.
According to the present results it can be concluded that explicit nonlinear redistribution of stresses can occur at changeable humidity already at statically determined beams. These stresses can be locally considerably larger than those obtained by linear theory that are considered in the design. At statically indetermined beams and frames significantly larger deviations can be expected, which is why we intend to focus also on this problem. The proposed research project includes the experimental monitoring of the behaviour of test beams in natural conditions through a longer period of time (2 or 3 years), upgrading the existing ssoftware for the numerical analysis of the humidity diffusion and mechanical response of the beam, parametric study of the influences of individual physical phenomena and material parameters, as well as the preparation of a database for the numerical analysis of the behaviour of glulam structures with respect to the possible spectra of natural conditions. In our reseasrch we will also focus on the corrections of stresses for the practical design of the beams, and we will study the possibilities and prepare the database for the stohastic modelling of the properties of timber as a nonhomogeneous material in the geometrical domain of the beam and weather conditions through a longer period of time.
