The load-bearing structure of portable exhibition stands needs to have its reliability verified through mechanical simulation. This process requires combining structural mechanics principles, simulation software functionality, and actual working conditions to ensure the design meets safety and stability requirements. Mechanical simulation, based on numerical techniques such as the finite element method, discretizes the continuous medium into finite elements. By solving equilibrium equations, geometric equations, and constitutive equations, it predicts the stress, strain, and deformation distribution of the structure under load. Its core lies in constructing an accurate digital model to simulate real-world stress scenarios and verifying whether the structure meets design specifications through iterative calculations.
First, a high-precision three-dimensional geometric model needs to be established, covering all load-bearing components, such as beams, columns, connection nodes, and supporting structures. The model must reflect the geometric characteristics of the actual structure, including cross-sectional shape, dimensions, and connection methods. For example, if aluminum alloy profiles are used, their elastic modulus, Poisson's ratio, and density must be defined in the model; if welding or bolted connections are involved, connection stiffness must be simulated through contact definitions or binding constraints. Geometric simplification must adhere to engineering specifications, removing details that do not affect mechanical properties, such as chamfers and small holes, to reduce computational load. However, critical areas must retain their complete features to avoid error accumulation.
Defining loads and boundary conditions is a crucial step in the simulation. The load-bearing structure of portable exhibition stands typically needs to withstand its own weight, exhibit weight, and crowd live loads. The self-weight is applied to the entire structure through gravitational acceleration; exhibit weight needs to be distributed to corresponding support points according to the actual layout; crowd loads need to consider dynamic effects, such as impacts from walking or jumping. Boundary conditions must simulate realistic constraints; for example, fixed ground supports must restrict all degrees of freedom, while temporary supports may only restrict partial displacement. Furthermore, temporary loads during transportation or assembly, such as additional forces from tilting or vibration, must be considered to ensure the structure's safety and reliability throughout its entire lifespan.
The choice of solver and parameter settings directly affect the accuracy of the simulation results. For linear static problems, such as stress analysis under constant loads, implicit solvers can be used, offering high computational accuracy and suitability for handling complex geometries and material nonlinearities. For dynamic responses, such as vibration or shock, an explicit solver must be used to capture transient mechanical behavior. The time step must satisfy the Courant condition to ensure computational stability; the convergence criterion must be set according to engineering requirements, typically requiring displacement or residual force to be less than allowable values. For nonlinear problems, such as material yielding or large deformation, an incremental iterative method should be used to progressively load and update the stiffness matrix to avoid numerical divergence.
In the post-processing stage, key results need to be extracted to assess structural reliability. Emphasis should be placed on the location and value of maximum stress, distinguishing between nodal stress and element stress to avoid misjudgments caused by stress concentration. The material yield strength should be compared to calculate the safety factor, ensuring that the stress level is below the design threshold. Deformation analysis should focus on overall displacement and local deflection to avoid excessive deformation affecting functionality. Modal analysis can assess the structure's natural frequencies and mode shapes to prevent resonance risks. Furthermore, mesh refinement studies are needed to verify the convergence of results, ensuring errors are controlled within allowable limits and preventing mesh quality from affecting the reliability of conclusions.
Engineering judgment and standard verification are the final steps in the simulation process. In accordance with industry standards, such as building structure load codes or exhibition equipment safety standards, assess whether the simulation results meet the requirements. For example, a safety factor typically needs to be greater than 1.5 to cover material performance fluctuations or load uncertainties. For critical structures, such as connection nodes or weak points, parametric analysis is required to study the impact of different design variables on reliability and optimize the structural form. Furthermore, simulation experience from similar cases can be referenced to compare the rationality of the results and ensure the design has engineering credibility.
Mechanical simulation needs to be combined with physical experiments to form a verification closed loop. Through static load tests or actual use tests, measure structural deformation and stress, compare the simulation data, correct model parameters, and improve prediction accuracy. For example, strain gauges can be placed on the exhibition stand prototype to monitor stress at key sections and verify the accuracy of the simulation results. This iterative process of "simulation-experiment-optimization" can significantly improve the reliability of the load-bearing structure of portable exhibition stands, ensuring its safe and stable operation under complex conditions.
