This manuscript provides a novel approach in the field of experimental and numerical investigation of mechanical properties of load carrying structures made of composite material. A combination of experimental and numerical simulation methods are used hereto. In the experimental part, different test configurations were taken into account. The excitation was performed by means of random and harmonic, single and multi point stimuli while the response measurement was done through contact and non-contact methods. The test results are applied in two ways: for the structural identification of the object and for the updating of the numerical model according to a range of experimental models obtained from test. The sources of the test data variabilities were related to the excitation and measurement technique applied for the investigated object. Numerical model updating and verification & validation included uncertainties of its parameters. It takes into account test data variability resulting from structural dynamic properties measurement and uses them to quantify uncertainties in model parameters updating. An optimization technique for the sensor number and location was applied. Such a combination demand to take advantage of knowledge from several fields: free vibrations, composite materials, measurement methods (especially experimental modal analysis), variability in measurement data, uncertainties in model parameters, signal processing, finite element method modeling, model updating, optimization, statistics. As a result of presented research set of updated numerical models was developed with an introduction of quality function assessing the influence of particular factors on model reliability related to overall workload demanded. Also a set of variable test data was assessed with a criterion of its application in industrial cases like Structure Health Monitoring.