Resumen en Inglés:

Abstract This study investigates the dynamic behavior and natural frequency of a geodesic dome constructed with recycled polypropylene type 5, emphasizing its feasibility as a sustainable structural solution. A dual approach combining computational modeling and experimental testing was implemented. The computational model incorporated the material's mechanical properties and was validated against a physical prototype subjected to vibration tests. Results revealed a strong correlation between experimental and analytical data, with minimal discrepancies attributed to model idealizations and real construction conditions. The dome's structural performance demonstrated high rigidity and efficient load distribution, confirmed by short vibration periods and balanced dynamic responses. This research highlights the potential of recycled plastic in geodesic structures, aligning with circular economy principles by promoting material reuse and reducing environmental impact. The findings provide valuable insights into innovative and sustainable construction practices, supporting the integration of recycled materials in dynamic structural applications.

Resumen en Inglés:

Abstract Current pipe jacking projects predominantly use C50 concrete pipes, which are prone to cracking and failure under jacking forces during complex construction. This study investigates the mechanical performance and failure mechanisms of C150 ultra-high performance fibre reinforced concrete (UHPFRC) pipes through full-scale trilateral loading test and numerical simulation. Key outcomes include crack load (232 kN/m), damage load (452 kN/m), and maximum displacements (64.3 mm horizontal, 71.6 mm vertical). Radial loading induced four primary cracks along the inner/outer left-right surfaces of the pipe, accompanied by extensive secondary crack networks. Damage progression began with concrete spalling at the top/bottom due to crack propagation, followed by reinforcement yielding and structural collapse. A predictive model for crack load and ultimate bearing capacity was developed, validated by experimental data. ABAQUS finite element simulations demonstrated excellent correlation with experiments, accurately reproducing macroscopic damage patterns. Notably, UHPFRC pipes exhibited 2.55-fold higher radial bearing capacity compared to C50 counterparts. This research establishes UHPFRC as a superior material for pipe jacking applications, offering enhanced structural integrity and reliability.

Resumen en Inglés:

Abstract The common treatment for calf fractures is cast immobilization, which limits the movement of the injured area and, causes muscle atrophy and joint stiffness. Wearing a cast for a long time can lead to problems such as itchiness and moist skin. To ameliorate these problems, this study designed a self-adaptive lightweight brace that provides strong patient protection throughout the rehabilitation cycle. The design of the brace is entirely based on the contour of the patient's leg, whereas topological optimization ensures that it meets requirements for lightweightness and air permeability. In the early stages of rehabilitation, the brace provided tight immobilization. During mid-rehabilitation, an automatic airbag filling system inflates in real time to ensure secure immobilization and prevent muscle atrophy or deformity. At the end of rehabilitation, a motorized drive system effectively rehabilitates patient movement. This study verified the effectiveness of the brace self-adaptive system through experimental validation, which involved the recruitment of three volunteers with varying leg circumferences. Volunteers with calf circumference of 34 and 36 cm were tested for reciprocal movement of the leg, and the angle was adjusted and fixed from 99° to 160° and from 104° to 173°, respectively. The automated airbag inflation system was tested on volunteers with calf circumferences of 34 cm. The results of this experiment demonstrated the effective support provided by the proposed brace system throughout the entire calf rehabilitation cycle, indicating its promising application in the medical field.