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In this study, calibrated hot box and finite element simulation methods were used to study the influence of a slotted web on the thermal performance of a lightweight steel stud composite wall. By comparing the results from the simulations and experiments, the accuracy of the finite element method was verified; this method was then used for parameter analyses. The results showed that the wall's thermal transfer coefficient is inversely proportional to increases in the length of the slot and height of the stud web, leading to improvements in the thermal insulation effect; vice versa, the wall thermal transfer coefficient increases when the slot transverse spacing and stud thickness increase, and the insulation effect correspondingly worsens. The stud spacing influences the insulation performance of the wall by changing the proportion of studs within a certain wall. The greater the proportion of studs, the greater the stud thermal bridging, the faster the thermal loss, and the worse the insulation effect of the wall. In practice, the height of the stud web can be set as required. Preferably, for practical applications, the number of rows of slots is 5–7, the length of the slots is 70–80 mm, the transverse distance of the slots is 6–8 mm, the thickness of each stud is 1 or 1.2 mm, and the distance of each stud is 600 mm. [ABSTRACT FROM AUTHOR]

• Major-axis flexural buckling of thin-walled channel members with slotted web are studied. • Regular and constrained shell finite element analyses are conducted. • The factors that are influencing the buckling behaviour are identified. • The numerical results highlight the importance of shear deformations. • Approximate analytical formulae are proposed to calculate the critical force for members with slotted web. In this paper elastic major-axis flexural buckling of thin-walled lipped channel column members with slotted webs is discussed. Though slotted webs are applied in order to enhance the thermal properties (this is why these members are also known as thermal studs), the slots have non-negligible effect on the mechanical behaviour. The primary aim of the presented research is to understand the behaviour, by identifying the major factors that influence buckling. As a tool, the recently developed constrained finite element method has been used, which makes it possible to separate the behaviour/buckling modes, as well as provides full control on the details of the calculations. It is found that, though other factors have some influence on the buckling results, the most important factor is the in-plane shear deformations of the slotted web, which may either be disregarded, or considered partially or fully in the calculations. An analytical model is also proposed for the calculation of critical force of slotted-web members, able to consider the effect of shear deformations, the degrading effect of the slots on the axial and bending rigidity, as well as the effect of longitudinal second-order strain terms. Numerical studies have been conducted covering a wide range of column lengths and slot geometries. The results of the numerical studies confirm the applicability of the constrained finite element method, and show that the analytical model estimates the critical loads with reasonable accuracy. [ABSTRACT FROM AUTHOR]