Rigidity of the Aluminum Window Profiles with Thermal Barrier

Abstract

Mullions are the main elements of windows that provide their resistance to wind load (lack of blowing under the wind pressure influence) and, as a result, affect the heat lost through windows because of air infiltration (or exfiltration). Therefore, when designing windows, it is necessary to pay special attention to issues of the assignment of stiffness indicators for their mullions. The work is devoted to the research of the moments of inertia of the window mullions made of aluminum profiles with thermal barrier used in the glazing of civil buildings. Generally, these profiles should be considered as a composite in terms of their static operation. Under the action of the load in the aluminum profiles with a thermal barrier, the shift of their individual structural layers relative to each other is possible. Laboratory tests of aluminum profiles with thermal barrier were conducted. Samples of profile elements had a length of 3 m and were fixed at the edges of the hinge supports. During the tests, they were sequentially loaded by a concentrated load force acting on the center of the span of the elements. Comparison of the data obtained during laboratory tests with the results of theoretical calculations showed that at the deflections of profile elements that do not exceed the normalized indicators (no more than 1/200 of the span), the shift of their layers can be ignored. In this case, the calculation of the moment of inertia of the aluminum profiles with thermal barrier can be performed without the thermal barrier rigidity.