The seismic performance of connection nodes in detachable container houses is one of the core indicators for evaluating their structural safety. These houses are based on modular design, achieving rapid assembly through the combination of standardized container units. As the mechanical transmission hub between these units, the seismic performance of the connection nodes directly affects the stability and reliability of the overall structure. Under seismic loading, connection nodes must withstand horizontal seismic forces, vertical loads, and complex stress coupling. Design or construction defects can easily lead to node failure, resulting in overall structural instability. Therefore, optimizing the seismic performance of connection nodes is crucial for improving the seismic resistance of detachable container houses.
In traditional connection methods, welded joints were widely used in detachable container houses due to their ease of construction and high connection strength. However, welded joints suffer from excessive rigidity, making them prone to brittle fracture of the weld due to stress concentration during earthquakes. For example, under reciprocating seismic loading, cracks easily form and propagate at the weld, ultimately leading to node failure. Furthermore, on-site construction of welded joints requires high worker skills; substandard welding quality further weakens seismic performance. In contrast, bolted connections, using high-strength bolts to achieve mechanical interlocking between container units, offer advantages such as convenient construction and high disassembly capability. However, ordinary bolted connections are prone to failure during earthquakes due to bolt loosening or shear failure, especially in multi-story or high-rise detachable container houses, where insufficient seismic performance is particularly pronounced.
To improve the seismic performance of detachable container house connection nodes, damping connection technology has become a research hotspot in recent years. This technology introduces energy-dissipating elements into the nodes, such as lead viscoelastic dampers and friction dampers, enabling the nodes to dissipate energy during earthquakes. For example, a damping connection node using lead viscoelastic dampers maintains its elastic phase under vertical loads and minor earthquakes, without significant deformation; however, under major earthquakes, the damper enters the energy-dissipating phase, dissipating seismic energy through the shear deformation of the lead core, reducing node stiffness, and decreasing internal forces in the main structure. This design not only avoids stress concentration at the nodes but also significantly improves the structure's hysteretic energy dissipation capacity, ensuring that the detachable container house maintains good horizontal lateral bearing capacity during earthquakes. Furthermore, optimizing the joint structure is also a crucial means of improving seismic performance. For example, adding beam-end connection reinforcements at the corner fittings of the container can enhance the local stiffness and load-bearing capacity of the joint; using cross-shaped steel plate clamps allows for the simultaneous connection of multiple corner fittings, simplifying the installation process while improving the overall integrity of the joint. These structural optimization measures, combined with damping technology, have enabled a qualitative leap in the seismic performance of detachable container house connection joints.
In practical applications, the seismic performance of detachable container house connection joints also needs to consider construction techniques and quality control. For example, during joint installation, it is essential to ensure that corner fittings are aligned and connectors are in tight contact to avoid uneven stress on the joint due to construction errors; simultaneously, the tightness of bolts and the working condition of dampers must be checked regularly to ensure the joint maintains reliable performance during long-term use.
The seismic performance of detachable container house connection joints is evolving from traditional rigid connections towards vibration reduction and energy dissipation. By introducing new energy-dissipating components, optimizing joint structure, and strengthening construction quality control, the safety and stability of detachable container houses during earthquakes have been significantly improved. In the future, with the development of materials science and structural mechanics, the seismic performance of connection nodes will be further optimized, providing a solid guarantee for the widespread application of detachable container houses in earthquake-prone areas.
