دانلود رایگان مقاله انگلیسی تجزیه و تحلیل تیرهای کامپوزیت فولاد ضد زنگ - الزویر 2018

abstract

Stainless steel is increasingly popular in construction projects owing to its corrosion-resistance, excellent mechanical and physical properties and its aesthetic appearance. The current paper is concerned with the use of these materials in steel-concrete composite beams, which is an entirely new application. Current design codes for steel-concrete composite beams are based on elastic-perfectly plastic steel material behaviour neglecting strain hardening. Whilst this is a reasonable assumption for carbon steel, stainless steel is a very ductile material which offers significant levels of strain hardening prior to failure. Therefore, current design provisions typically result in inaccurate and overly-conservative strength predictions when applied to stainless steel composite beams. The current study presents for the first time, an analytical solution for predicting the plastic bending capacity of stainless steel–concrete composite beams with either full or partial shear connection. This method is a development of the continuous strength method (CSM). Since the analytical analysis requires complex mathematical solution, a simplified analytical solution is also proposed, utilising some of the assumptions in Eurocode 4. There are no tests currently available in the literature for stainless steel-concrete composite beams. Therefore, a finite-element model is developed and validated against a number of experimental results for composite beams made from normal or high strength carbon steel. The validated numerical model is then used to investigate the accuracy of the proposed analytical solution. It is concluded that both the full and simplified analytical solutions are reliable and the simplified analytical method provides a straight forward design tool for practical engineers.

7. Conclusions

Current design codes for steel-concrete composite beams neglect strain hardening of the steel member. Although this is a reasonable assumption for carbon steel, stainless steel is a very ductile material which demonstrates significant levels of strain hardening. The current research presents an adaptation of the continuous strength method (CSM) for composite beams made from stainless steel, to predict the plastic bending moment capacity for members with full and partial shear connection. Two different models are presented, namely a full, detailed model as well as a more simplified approach. Since no tests have been conducted on stainless steel-concrete composite beams, a validated finite-element model is employed to investigate the accuracy of the proposed analytical approach. The analytical analysis in the full model, in particular, requires complex mathematical solution and therefore a simplified analytical solution is also proposed, utilising the assumptions of Eurocode 4. It is concluded that both the full and simplified analytical solutions presented in this study provide an accurate prediction of the bending capacity. Moreover, the simplified analytical approach also provides a straight-forward design tool for practical engineers, which can be applied for composite beams with full or partial shear connection.