## 3 Research Method
### Experimental Test
The temperature field test scheme of the Tien Rice Cube is shown in Figure 3. The conch-shaped single-layer steel lattice structure of the Yujiabu Railway Station Building is covered by ETFE membrane and glass; [PERSON] selected 11 steel members from the steel structure for temperature testing [119], and these members are shown in Figure 4. In order to analyze the differences in temperature characteristics between the members under the glass roof and the ETFE membrane, members 1, 2, 3, 5 and 11 were set under the glass roof, and the other 7 members were arranged under the ETFE membrane. In addition, the steel lattice structure can be divided into three parts: upper girder, upper lattice shell, and bottom girder; members 2 and 5 were located in the upper girder, member 11 was located in the bottom girder, and the other 8 members were located in the upper lattice shell. Similarly, four temperature sensors were arranged along the mid-span sections of each of the monitored rectangular or circular members. Figure 3: _Cont_. Figure 4: _Cont_. Figure 3: Temperature field test scheme of the Tien Rice Cube (structural diagram, measuring point layout) [29]. The temperature field testing of bridges is usually carried out through the health monitoring system [120]; for example, 250 temperature sensors were installed in the six sections of the Confederation Bridge in order to monitor its real-time temperature field at hourly intervals [121]. In steel truss bridges, the layout of temperature sensors is similar to in space structures, and a limited number of steel trusses will be monitored according to the research objective. The Dashengguan Yangtze River Bridge and the Tongling Yangtze River Bridge are two typical steel truss bridges, the monitored members of which belong to the same cross-section in the longitudinal direction of the bridge in order to study the temperature difference between truss members, and several temperature sensors are also arranged in the mid-span section of the same truss member to study the temperature gradient of the truss section [43; 44]; temperature tests of some other steel truss bridges also use this method for the layout of their temperature sensors [45]. Steel box girders in the bridge can be regarded as slender steel members, and the temperature gradient along the longitudinal direction is relatively small and can be ignored, which has been verified by previous studies [51; 122]. Table 2 gives five temperature field test cases for steel box girders. In most test cases, only one section was arranged with temperature measuring points, and the temperature difference along the longitudinal direction of the steel box girder was ignored. Although four sections were selected at which to set measuring points in the test case of Runyang Bridge's steel box girder, the test data of Section III was mainly used for analyzing temperature field characteristics, and the temperature difference between sections were relatively small. All test results show that the temperature distribution of the cross-section is significantly non-uniform, and this non-uniformity was reflected in the vertical and horizontal temperature differences. Therefore, it is suggested that only one section be selected for temperature field monitoring, while the number of temperature sensors should be as large as possible in order to fully reflect the non-uniformity of the cross-section temperature field. In the daily state, the stay cables of cable-stayed bridges are in protection sleeves, and temperature monitoring is difficult to realize with conventional temperature sensors.