Yazarlar
- Ozyurt, E.(2)
- Wang, Y.C.(2)
Yayınlar
- MakaleYalnız künye2025Scopus SJRQ1Influences of chord pre-stress on CHS X-joints with high-strength-steel at various temperatures
Ozyurt, E.; Wang, Y.C.
This study examines the influence of chord pre-stress on the behaviour and load resistance of Circular Hollow Section (CHS) X-joints with High Strength Steel (HSS) at various temperatures. This investigation uses a total number of seven hundred and four Finite Element simulation results to evaluate the level of accuracy of current Eurocode and CIDECT design guidelines in predicting the high-temperature resistance of these joints. The numerical simulations investigate the effects of changing brace-to-chord diameter (β), chord semi-diameter-to-thickness (γ), and brace-to-chord thickness (τ) ratios, as well as different prestressing levels (np) and temperatures (θ). The γ and τ ratios have a limited effect on the normalised joint strength, but the β ratio, and the prestressing level are highly influential. At ambient temperature, the CIDECT design approach is a more suitable method for calculating the chord pre-stress reduction factors for S355 joints. For HSS X-joints, the constant modification coefficient of 0.80 is inadequate, and this paper has proposed a new modification coefficient as a function of the pre-stress level. At elevated temperatures, the ambient temperature resistance of CHS X-joints can be modified by the reduction factor of the Young's modulus for S355 steel and that of the yield stress for S960 steel.
AtıfScopus3WoS3OpenAlex2
İncele - MakaleYalnız künye2021Scopus SJRQ1Static resistance of axially loaded multiplanar gap KK-joints of Circular Hollow sections at elevated temperatures
Wang, Y.C.; Ozyurt, E.
This paper presents the results of a numerical investigation of the behaviour, and proposes a method to calculate the static resistance of axially loaded Circular Hollow Section Double K-joints (DKK) at elevated temperatures. This type of joints is widely used in building construction, but currently, there is no method to calculate their static resistance at elevated temperatures. The numerical investigations of this paper cover a wide range of design parameters, including brace axial load combination, joint temperature, angles between brace members, longitudinal and transverse gap sizes, chord diameter to thickness ratio and brace diameter to chord diameter ratio. The results of this paper indicate that the ratio of joint elevated temperature resistance to ambient temperature resistance may be lower than the reduction factor for the yield strength of steel at elevated temperatures. There are two joint failure modes, one for small and one for large transverse gap. These failure modes and the demarcation between small and large gaps are independent of joint temperature. For joints with large gap, the ratio of joint resistance at elevated temperature to that at ambient temperature is close to the average of steel yield strength and Young's modulus reduction factors at elevated temperature. For joints with small gap, the joint resistance ratio follows the steel Young's modulus factor variation at elevated temperature if all four braces are under compression, but the trend changes to the average ratio of steel Young's modulus and yield strength reduction factors if the axial brace loads are balanced (compression in two brace members equal to tension force in the other two brace members). Linear interpolation can be applied between these two different loading cases.
AtıfScopus17WoS15OpenAlex17İncele