Acessibilidade / Reportar erro
Latin American Journal of Solids and Structures, Volume: 21, Número: 6, Publicado: 2024
  • A physics-based fast algorithm for structural responses of generalized rotationally axisymmetric structures: the generalized rotation-superposition method Original Article

    Yang, Mao; Zhang, Jun; Chen, Hao; Yang, Jialin; Mao, Yongjian

    Resumo em Inglês:

    Abstract Fast calculations are widely required in the traditional applications and the emerging digital twin fields. For those considerations, a novel physics-based fast algorithm, namely generalized rotation-superposition method, is proposed for fast calculating linear elastic responses of generalized rotationally axisymmetric structures under arbitrary mechanical loads. This improved method breaks through the limitations of the previous basic rotation-superposition method in rotational similarity of load and structural axisymmetry, and greatly expands its application scope. In this paper, firstly, the basic theory of the rotation-superposition algorithm is introduced; secondly, the theoretical model of the generalized rotation-superposition method is established; thirdly, the effectiveness and accuracy are verified by using finite element simulations; finally, through a complex case study, the applicability of the generalized rotation-superposition method for complex engineering problems and its advantages in efficiently obtaining massive amounts of data are further illustrated.
  • Modelling and non-linear analysis of beam-elements in reinforced concrete Vierendeel sandwich plates considering nodal stiffness domain effects Original Article

    Sheng, Xia; Xiao, Jianchun; Guo, Hua; Zhang, Hanming; Liu, Cong; Ma, Kejian

    Resumo em Inglês:

    Abstract The results of finite element analysis of reinforced concrete Vierendeel sandwich plates (RCVSP) using beam-plate elements calculation model show a significant discrepancy with the actual results. Considering the structural characteristics of RCVSP and the calculation method of beam-elements, the assumption of the existence of nodal stiffness domain effects (NSDE) is proposed for its beam-plate elements calculation model. In order to verify this assumption, the existing experimental data of RCVSP is used to compare with the finite element analysis results of the beam-plate elements calculation model. The analysis results show that there is NSDE in the finite element analysis of RCVSP using beam-plate elements calculation model. The beam-elements calculation model FeaR1, which fully considers NSDE, can effectively restore the calculated stiffness lost. Compared with the solid-elements calculation model of RCVSP, the calculation model FeaR1 is more convenient for modeling, enhances computational efficiency, achieves the stiffness restoration rate of approximately 80%, and maintains the average error of no more than 16%.
  • Flexural and Shear Behavior of Hybrid Deck Structures Composed of Textile Reinforced Concrete Integrated Formwork and Reinforced Concrete Original Article

    Nguyen, Huy-Cuong; Pham, Thi-Thanh-Thuy

    Resumo em Inglês:

    Abstract The integration of textile-reinforced concrete (TRC) and reinforced concrete (RC) has recently emerged as a promising strategy for developing hybrid structures. This study examines the flexural and shear behavior of a hybrid deck combining TRC-integrated formwork and RC through 3-point and 4-point bending tests on eight specimens with aspect ratios (a/d) ranging from 1.6 to 2.9. The test results show that the TRC integrated formwork, with its customizable cross-section and strong load-bearing capacity, is ideal for bridge deck structures. Its cracking load exceeds the required construction strength. Furthermore, the TRC formwork enhances load-carrying capacity, stiffness, and ductility, serving as an effective shear connector between concrete layers. The hybrid deck specimens display minimal, fine cracks, indicating enhanced crack resistance, improved serviceability, and reduced crack occurrence. Shear compressive and diagonal shear failures were noted in specimens, but the TRC formwork successfully averted transverse cracks at the interface, ensuring enhanced interfacial bond strength and structural integrity.
  • Study on Scaled Model with Distortion of Free Vibration of Longitudinal Ring-Stiffened Large Thin-walled Cylindrical Shell Original Article

    Zheng, Ce; Yang, Yanguo; Yu, Wei; Chen, Shihao; Zhang, Lu; Zhao, Shenghua

    Resumo em Inglês:

    Abstract For the design of scaled model and similarity prediction of vibration of 300,000m3 blast furnace gasholder body, based on energy method and discrete stiffening theory, the scaling principle relation of gasholder body free vibration are derived. By using the thickness scale factor of the gasholder body skin and rib is distorted, and utilizing the stiffness equivalence, respectively, gasholder body scaled models (stiffened rib equivalent to rectangle) with geometric distortion and with both geometric and material distortion are designed and fabricated respectively. The free vibration of distortion similarity prediction of gasholder body prototype is carried out by the method of simulation and test. Results show that both two kinds of gasholder body scaled models, can predict the prototype frequency more accurately by using the similarity coefficient calculated by the average bending stiffness of column, ring rib, and wind-resistant ring. The proposed design method and scaling principle relation for gasholder body scaled model with free vibration and distortion are suitable for the design of scaled model distortion and similar prediction of free vibration of longitudinal ring-stiffened large thin-walled cylindrical shells with T-shaped and I-shaped stiffeners.
  • Optimization of Profiled Steel Deck Composite Slab Strengthened with CFRP: A Finite Element Analysis Approach Original Article

    Karthiga, S; Umamaheswari, N

    Resumo em Inglês:

    Abstract This work leverages Finite Element (FE) modelling to optimise the deck geometry in continuous composite slab systems, focusing on trapezoidal profile decks. Subsequently, it examines the effectiveness of reinforcing the hogging moment area with Carbon Fiber Reinforced Polymer (CFRP). The main objective is to improve the structural performance when subjected to static loads by optimising geometric factors such as deck height and thickness. The deck profile that yielded the best results had a height of 60 mm, a thickness of 1 mm, and a shear span of 850 mm and resulted in a 7.6% increase in the ultimate load compared to a deck with a thickness of 0.75 mm. The study also assesses the impacts of CFRP reinforcement configurations. The optimal outcome was attained by utilising carbon fiber reinforced polymer (CFRP) sheets that spanned the whole width of the slab for a length of 1.7 m, resulted in a significant 43.17% enhancement in ultimate load. The CFRP enhanced slab, which spans the whole width, demonstrated a maximum load-carrying capability of 176.78 kN. Theoretical analysis indicated a high level of concurrence with FEM.
  • Study on the structural damage detection method using the flexibility matrix Original Article

    Zhang, Muyu; Peng, Xiaoyang; Li, Yujia; Wang, Ziping; Zhu, Jianguo; Zhang, Jian

    Resumo em Inglês:

    Abstract The flexibility matrix finds extensive application in detecting damage in civil and mechanical engineering structures, a focus explored in-depth within this paper. This study meticulously examines distinct components of the flexibility matrix, namely the proposed Diagonal of the Flexibility Matrix Vector (DFV) and a singular row/column of the flexibility matrix (RFV). Both DFV and RFV can be represented uniquely as a specialized form-a weighted combination of the Hadamard product of two mode shapes. Sensitivity analysis reveals that DFV undergoes a sharp change in proximity to damage, establishing it as a dependable indicator for pinpointing damage locations. Conversely, this characteristic is not consistently observed with RFV. The results of numerical simulations conducted on a 16-story frame structure corroborate the outcomes of the sensitivity analysis, underscoring the efficacy of DFV not only in localizing damage but also in gauging its severity. To illustrate the potential and limitations of DFV/RFV in practical scenarios, damage localization for the I-40 Bridge is provided.
  • Research on the damage resilience model of a new steel-concrete inclined column transfer structure Original Article

    Tang, Sen; Xie, Zongyan; Shen, Bo; Ma, Kejian; Zheng, Tianhong

    Resumo em Inglês:

    Abstract For the new type of steel-concrete inclined column transfer structure (NSCICTS) with better lateral stiffness and ductility, the existing damage model and hysteresis model are difficult to accurately express the asymmetry of its test restoring force curve and the serious pinching phenomenon of the hysteresis curve, respectively. In this paper, an asymmetric damage model is firstly established according to the asymmetry of the curve, and the comparison with the existing symmetric damage model shows that the asymmetric damage model proposed can reflect the actual damage of the component or structure. Then, a simplified hysteresis loop model with a longer slip segment is established, and the damage formulas of the stiffness and residual deformation are established. Finally, the hysteresis rules are given, and the comparison with the test hysteresis curve shows that the proposed model can better simulate the structural mechanical properties. The model provides a theoretical basis for the overall nonlinear seismic analysis of the NSCICTS and other similar structures.
Individual owner www.lajss.org - São Paulo - SP - Brazil
E-mail: lajsssecretary@gmsie.usp.br