This paper proposes a new type of composite box beam combined with cold-formed thin-walled steel and glued laminated timber to develop green building structures while improving the load-carrying capacity of a single steel girder and glued timber girder. Two composite beams composed of laminated timber and Q235 cold-formed thin-walled steel were designed and fabricated. Then, the shear performance test with quadratic loading was carried out to analyze the load carrying capacity, damage modes, and deformation characteristics of the test beams, as well as their influencing factors. Subsequently, a finite element model of the composite beam was established, and the loading mode was the same as that of the test to further study the parameters affecting the shear performance of the composite beam. The results of the study indicate that steel and glued timber in composite beams connected by adhesive bonding can work and deform together under load and each give full play to its material properties, especially the composite beams, which exhibit higher shear strength than a steel or timber beam. The effects of parameters such as steel cross-sectional area, shear span ratio, steel skeleton form, and steel cross-sectional strength on the shear capacity of the composite beams were observed, among which the shear span ratio had the greatest effect on the shear capacity of the composite beams. The shear capacity decreased by 14.3% and 19.5% when the shear span ratio was increased from 1.5 to 2.0 and 2.5, respectively. The shear capacity of the combined composite beams increased by 10.6%, 6.3%, and 5.8% when the thickness was increased from 1.5 mm to 2.0 mm, 2.5 mm, and 3.0 mm, respectively. When the combination of the steel cross-section was a box beam, the overall shear-bearing capacity could be increased by 12% compared with the “I” type composite beam, although its shear stiffness was close to that of the “I” section composite beam.

In order to mitigate the vibration caused by fluid–structure interaction in water-conveying pipelines, a semi-active control method based on a magnetorheological (MR) damper is proposed. First, the partial differential equation governing the pipeline micro-element, which is simply supported at both ends, is formulated. This equation is then transformed into state-space expressions through non-dimensionalization and the Galerkin method. Based on passive dissipative control theory, a semi-active control law ensuring Lyapunov global asymptotic stability is derived based on the relative motion between the dynamic vibration-absorbing mass and the pipeline. Next, an on–off control algorithm is designed for the MR damper. The results of simulation and hardware-in-loop experiments demonstrate that the semi-active control law can significantly reduce the vibration of the pipeline system. The contribution of this research is to propose a new MR tuned mass damper (MR-TMD) to suppress vibration in water-conveying pipelines. The proposed MR-TMD scheme and its control method provide a theoretical basis and practical reference for the engineering application of semi-active vibration control in water-conveying pipelines.