Warning message occurs when performing design response spectrum analysis.
The warning message is caused by the value of the natural frequency of the structure being larger than the frequency range of the defined design response spectrum. If the warning message is not taken into account, it will not reflect the full dynamic characteristics of the structure. Therefore, you need to increase the cycle range of the design response spectrum using the method below.
1. If a warning message has occurred, first check the maximum period of the structure or check the period value output from the warning message.
Result > Tables > Results Tables > Viberation Mode Shape
2. Once you have determined the maximum period of the structure, set the period range of the design response spectrum to a value greater than the maximum period of the structure by entering the Max. Period input value in the figure below. (The default value is 6 seconds).
[ Define Design Response Spectrum Dialog Box ]