Force Analysis of Container Houses

The force analysis of container houses requires a comprehensive consideration of structural forms, material properties, connection methods, and load types. Their mechanical performance achieves overall stability through the synergistic effect of the frame and corrugated plates.

1. Structural Forms and Material Properties

Container houses use a steel frame as the core load-bearing system, typically employing high-strength steel (such as Q345) to fabricate corner columns, side beams, and cross beams, forming a space truss structure. The frame is integrated through welding or bolting, providing a clear load transfer path. Corrugated steel plates, as the enclosure structure, not only bear vertical loads but also participate in the horizontal lateral force resistance system through the 'diaphragm effect'. The wavelength, wave height, and thickness (usually 2-3mm) of the corrugated plates directly affect their stiffness. The equivalent elastic modulus (E1) in the direction perpendicular to the corrugations is only 5% of that of steel, while in the parallel direction (E2), it can reach 106.5% of that of steel. This anisotropic property plays a crucial role in lateral force resistance.

2. Connection Nodes and Overall Stability

The connection between the frame and corrugated plates uses self-tapping screws or rivets, forming semi-rigid nodes. Under horizontal loads (such as wind and earthquakes), stress concentration at the nodes needs to be alleviated through reinforcement measures (such as adding angle steel or node plates). In multi-story container houses, the connection between upper and lower floors uses high-strength bolts or welding to ensure overall coordinated work. For example, a double-story container fire station simulates the lateral stiffness of corrugated plates through equivalent cross bracing, meeting the seismic requirements of GB 50017—2017 'Steel Structure Design Standard'.

3. Impact of Openings on Force Performance

To meet lighting and ventilation needs, container houses often have door and window openings, which weaken the overall structural integrity. When the opening ratio (the ratio of the opening area to the wall area) exceeds 30%, reinforcement around the openings is required, such as adding steel beams, columns, or diagonal braces. Finite element analysis shows that the structural stiffness significantly decreases after openings are made, but through reasonable reinforcement (such as adding structural purlins or increasing the density of self-tapping screws), it can be restored to more than 80% of the original design.

4. Load Transfer and Seismic Design

The load transfer path in container houses is: enclosure structure → frame → foundation. Under earthquake action, the light steel structure dissipates energy through plastic hinges, and the 'diaphragm effect' of the corrugated plates reduces frame lateral displacement. In seismic design, it is necessary to control the width-to-thickness ratio of components (such as the width-to-thickness ratio of corner columns ≤ 15) to avoid local instability. For example, the quick-assembly container houses from Suzhou Zhongnan Steel Structure Co., Ltd. use a fully welded frame with a seismic rating of 8, meeting the requirements of GB50011-2010.