## 2 Methods
### Numerical Simulation Method  
Many deficiencies in the similarity relationships derived from the classic similarity theory have not been able to fully meet the development requirements of current model tests [12; 13; 14; 15; 16; 17; 18; 19; 20]. To solve this problem, ABAQUS 6.14 (2014, Dassault SIMULIA, Inc., Providence, USA) was used to establish an accurate node finite element model to simulate similar errors. The element type of the finite element model in this paper is the linear reduced integral element C3D8R, the grid control size of the beam-column member is 15 mm, the end-plate is 4 mm, and the bolt is 1.4 mm. The model in this paper adopts the loading method of displacement control. The analysis in this article is a static analysis, so the constitutive relationship of steel uses a trilinear model. The strength grade of the beam and column steel is Q345B, the ultimate strain is 0.1, and the elastic modulus is taken as 206,000 MPa. The bolts are all 10.9 high-strength friction-type bolts, the ultimate strain is 0.1, and the elastic modulus is 210,000 MPa. The size parameters of the model are shown in Table 4 and Figure 1.  
To make the simulation as close as possible to the actual situation, fine modeling was performed at the boundary of the nodes in the finite element analysis simulation, including ribs and stiffeners, which are consistent with the actual conditions of the actual test. Column length is the distance between the inflection points of the upper and lower adjacent layers in the actual structure. The model adopts the form of column-head loading and beam-end restraint, the bottom of the column is simulated as a hinged bearing constraint, and the beam ends are telescopic sliding bearings. The contact surface of the column and the end-plate was set to contact. The definition of the contact properties was divided into two parts. The normal action was defined as the hard contact type, the tangential action was defined as the Coulomb friction type, and the friction coefficient was defined as 0.4. The model is shown in Figure 2. The boundary conditions are shown in Figure 3. Two materials were used in the \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Prototype** & **Component Modulus (mm)** & **Model** &
\begin{tabular}{c} **Component Modulus of Completely** \\ **Similar Conditions (mm)** \\ \end{tabular} \\ \hline \(\mathrm{B_{P}}\) & HN\(300\times 200\times 8\times 12\) & \(\mathrm{B_{m}}\) & \(150\times 100\times 4\times 6\) \\ \(\mathrm{C_{P}}\) & HN\(300\times 300\times 10\times 15\) & \(\mathrm{C_{m}}\) & \(150\times 150\times 5\times 7.5\) \\ \(\mathrm{E_{P}}\) & \(250\times 500\times 16\) & \(\mathrm{E_{m}}\) & \(125\times 250\times 8\) \\ \(\mathrm{BL_{P}}\) & M20 & \(\mathrm{BL_{m}}\) & M10 \\ \hline \hline \end{tabular}  
* \(\mathrm{B_{P}}\): beam of prototype; \(\mathrm{C_{P}}\): column of prototype; \(\mathrm{E_{P}}\): end plate of prototype; \(\mathrm{BL_{P}}\): bolt of prototype; \(\mathrm{B_{m}}\): beam of model; \(\mathrm{C_{m}}\): column of model; \(\mathrm{E_{m}}\): end-plate of model; \(\mathrm{BL_{m}}\): bolt of model. HN: Narrow flange H-beam. M: Bolt specifications.  
\end{table} 
Table 4: Component modulus of completely similar conditions. Figure 1: Schematic diagram of component dimensions. finite element model, which were high-strength bolts and beam-column steel. The material properties of the two steels are shown in Table 5.  
In order to avoid the simulation error caused by the size effect of the unit, the unit size ratio of the model and the prototype is set to a ratio that meets the similar ratio, see Table 6 for details. By comparing the stress distribution of the completely similar model and prototype, the accuracy of numerical simulation is illustrated.