There is no problem in the new design, but the structure that cannot exceed the performance

[cenksonmez]

Greetings, The attached file is the ide file of a new build. No problems with analysis and account reports. When performance evaluation analysis is performed on the same file, I encounter the result of a crash. In the future, we will encounter this problem when we perform performance evaluation analysis on the structures that we calculate today, which are not problems. If there is a problem in the structure, we should see it in the first analysis. If there is no problem, why do we get the result of failure from performance evaluation? Best regards

 

[Ismail Hakki Besler]

Re: Your structure, which did not have any problems in the new design but could not exceed the performance According to DGT, your structure is quite borderline in the calculation. Column capacity ratios 95% and above in many columns. Performance calculation and calculation according to strength are different calculations. Especially linear performance analysis gives very approximate results. The calculation according to the strength and the linear performance calculation should not be compared. If this structure is a structure that has not been built yet, design it as a more rigid structure. If it is an existing structure, strengthen it. It also seems to provide relative floor offsets for flexible jointing. If you check the other option, you will see that the relative floor offsets are not provided. We cannot say that a building that does not meet the relative story drift condition meets the earthquake code requirements.

 

[oguzcan]

Hello there; The performance analysis you are using is the performance analysis for existing buildings. If you were to compare the performance analysis with DGT for new buildings, you would get relatively close results. The DGT approach and the Performance calculation (linear performance, thrust analysis or time history) are accounts that differ considerably from each other. Therefore, it may not give similar results for all structures. The reason for this is that the loading conditions and material models are different from each other. In TBDY, separate material strength coefficients are given for DGT, performance of new structures and performance of existing structures. The performance targets of the structures designed with DGT are foreseen as KH (Controlled Damage). The material strengths used here are obtained by dividing the characteristic strength by the factor of safety. For example, the characteristic compressive strength for the concrete C30 concrete model is fck = 30 MPa. The strength used in DGT is fcd = fck/1.5, that is, fcd = 20 MPa. In addition, it is multiplied by 0.85. Subsequently, a design result is obtained by using various coefficients and R coefficient in loading combinations (such as R=8). Considering TBDY 2019 Article 5.4.1.5 (b) in the performance analysis for new buildings, it is said that material strengths should be taken as "expected (average) strengths". Table 5.1 shows how to obtain these material strengths. Therefore, we have to use fce=1.3fck instead of fck when finding strength here. In this case, the material strength increases to 39 MPa. For existing buildings we need to look at TBDY 2019 Chapter 15. In TBDY Section 15.2.12, it is said that "existing material strengths" should be used in the calculation of element capacities. In addition, the strengths of these materials can be reduced according to the level of knowledge obtained from the buildings (Table 15.1). In this case, the material strength fck = 30MPa is used, even if the extensive knowledge level is used. When a performance analysis is made for new buildings and existing buildings using the same steps in the regulation, different results are obtained. Because different material models are used. Apart from this, linear performance analysis can be punishing in some cases because it is an approximate method. Best regards...