Home Dynamic response of a two-story steel structure subjected to earthquake excitation by using deterministic and nondeterministic approaches
Article Open Access

Dynamic response of a two-story steel structure subjected to earthquake excitation by using deterministic and nondeterministic approaches

  • Mustafa Qasim Dows EMAIL logo and Hayder A. Al-Baghdadi
Published/Copyright: July 3, 2023

Abstract

An earthquake is a random phenomenon in its intensity and frequency content. Since the earthquake is a signal that contains a band of frequencies, each frequency has a different energy. This means that the response of buildings to earthquakes depends not only on the intensity of the earthquake but on its frequency content as well. In this study, two different approaches have been used: deterministic approach which is the time history analysis to show how the intensity of earthquakes affects the building response, and the nondeterministic random vibration approach, which is to clarify the response in the frequency domain and to show the effect of dominant frequencies of the earthquake. Both a prototype and a 1:6 scaled model was used to simulate a two-story steel building. In the experiential part, a shaking table was used to simulate a 1:6 scaled El-Centro 1940 NS earthquake as a base excitation with different intensities (0.05, 0.15, and 0.32g). In the theoretical part, Abaqus software was adopted to simulate the numerical model of the building. The results showed that the deterministic approach may be a non-conservative approach.

1 Introduction

Since earthquakes are completely random excitation processes, the analysis of a structure’s seismic response must utilize the random vibration technique. However, random vibration methodologies have not been widely used in the research and design of structures due to the complexity of the analysis and low processing efficiency. As an alternative, time history analysis and the response spectrum approach have generally been used to study how buildings and other structures respond to seismic forces.

The randomness of ground motions requires the use of the random vibration theory in seismic response analysis. As a general rule, random vibrations can be divided into stationary and non-stationary types. If the cumulative averages for a random stimulation are not dependent on time, it is referred to as non-stationary. Due to simplicity, the designers adopted a stationary random vibration approach as a nondeterministic one [1]. It is essential for engineers to conduct a dynamic time history analysis of structures during the entire seismic excitation process in order to thoroughly investigate the structural energy dissipation characteristics and failure processes [2].

Multi-source random dynamic excitations can be identified by using the power spectral density (PSD) of dynamic responses and structural features, which is known as the so-called multi-input-multi-output problem for engineering structures subjected to numerous stationary random dynamic loads [3]. The second type of inverse problem has been extensively investigated and developed over the past few decades, especially focusing on the identification of dynamic loads in the frequency and time domains, as well as the identification of dynamic loads.

Depending on the randomness of the dynamic loading, the approach of load identification can be categorized as: (i) deterministic approach and (ii) nondeterministic or stochastic approach. In this study, the two approaches were used. The first one, deterministic approach, which is the time history analysis, was used to show how the intensity of earthquakes affects the building response. On the other hand, the second approach, which is the nondeterministic random vibration approach, was used to clarify the response in the frequency domain and to show the effect of dominant frequencies of the earthquake.

The analysis of multi-degree-of-freedom (MDOF) systems and buildings by using the nondeterministic approach had been studied by many researchers over the past 20 years. In 2002, Al-Baghdadi [4] studied the response of MDOF system subjected to a nonstationary stochastic ground motion. In this study, the formulation of the evolutionary correlation and PSD matrices was developed by using classical-complex model analysis approach and the effect of multiple-support excitation was considered. Li et al. [5] developed a pseudo-excitation method (PEM) to study the response of tall buildings subjected to seismic excitation by using the random vibration analysis. Fei et al. [6] investigated the structural systems subjected to stationary excitation with structural topology optimization orientation. He proposed an approach to transform the acceleration excitations in the base of the large mass system into force excitations. Rezayibana [1] adopted a PEM to analyze a MDOF system for different conditions of soil. On the other hand, several studies adopted the shaking table approach to evaluate the behavior and response of structures subjected to seismic excitations. Al-Baghdadi [7] studied the behavior of a 1:6 scaled two-story RC building under skew seismic excitations. A deterministic approach was adopted in the theoretical part, while a shaking table was developed by the author to cover the experimental part. A very good agreement between the theoretical and shaking table results, for both elastic and inelastic responses, were achieved. Liu et al. [2] studied the dynamic response and dynamic reliability assessment of a multi-story building under seismic excitations by using a shaking table in conjunction with a stochastic approach through a probability density evolution method. In 2020, a 1:4 scaled three-story steel structure was studied by Jing et al. [8] experimentally through a shaking table under biaxial base excitation. They also developed a numerical model to simulate the dynamic behavior of the system. The developed numerical model was verified depending on the experimental results.

In this study, three different approaches were adopted to study the dynamic behavior of a 1:6 scaled two-story building. The three approaches are: deterministic time history analysis approach, stationary stochastic analysis approach, and experimental shaking table approach.

2 Experimental work

2.1 One-sixth scale steel frame model

A square-shaped steel building in plan was designed under the influence of gravitational and earthquake loadings. The prototype is two-floor building, each floor has four columns and four beams, on which the slab layer rests. The building was designed according to the American Institute of Steel Construction [9] requirements. The columns were chosen from HEA 320, the beams from IPE 400, the roof was made of concrete with thickness of 10 cm, with four floor beams of IPE 200. The steel modulus of elasticity of E = 200,000 MPa, Poisson’s ratio of v = 0.3 , yield stress of 306 MPa, damping ratio ξ = 2 % (this study considers damping as a constant damping), and a density of 7,850  kg / m 3 were adopted as physical parameters. As for the actual dimensions of the prototype building, each floor is 4.5 m high and 3.6 m between the columns from center to center, and with fixed support, as shown in Figure 1.

Figure 1 
                  Prototype structure details.
Figure 1

Prototype structure details.

Then, the prototype building and the earthquake were modeled with a scaling factor S L = 6 (1:6), according to Harris and Sabnis 1999 [10] by the pi theory, as listed in Table 1. All dimensions and details of the model steel structure is shown in Figure 2.

Table 1

Similitude requirements for the model structure [10]

Quantity Symbol Dimension Scale factor
Geometry
Linear dimension L L S L
Displacement δ L S L
Frequency ω T 1 S L 1 / 2
Material properties
Modulus of elasticity E F L 2 S E
Stress σ F L 2 S E
Strain ε 1
Poisson’s ratio ν 1
Mass density ρ F L 4 T 2 S E / S L
Energy EN FL S E S L 3
Loading
Force Q F S E S L 2
Pressure q F L 2 S E
Gravitational acceleration g L T 2 1
Acceleration a L T 2 1
Velocity v L T 1 S L 1 / 2
Time t T S L 1 / 2
Figure 2 
                  Model structure details.
Figure 2

Model structure details.

2.2 Mass similitude

For accurate modeling of dynamic behavior, the model’s mass similitude must be satisfied. Using constant acceleration scaling and the same material for the model, more mass must be added to compensate for the difference between the needed and given material densities, according to the similitude requirements listed in previous literature [10].

(1) M m i = M p i S L 2 M om i ,

where M m i is the additional mass to be added to the model’s i th story, M p i is the prototype’s i th story dead load, and M om i is the own weight of the model’s i th floor.

M m i = 253 kg .

The mass added to the model for every story is shown in Figure 3.

Figure 3 
                  The model on the shaking table with added mass.
Figure 3

The model on the shaking table with added mass.

2.3 Shake table

There is no other experimental equipment that tries to recreate the true nature of the earthquake input like shaking tables, hence they are important in earthquake engineering. Using a ground motion at the structure’s base, they simulate realistic inertia forces over the entire mass of the structure. The displacements and strains that result from the response are caused by these forces. The shaking table motion has a one-directional horizontal excitation only with the ability of model skewness (Figures 46) (Table 2).

Figure 4 
                  The shaking table, accelerometer, and strain gages.
Figure 4

The shaking table, accelerometer, and strain gages.

Figure 5 
                  The LVDT of each story.
Figure 5

The LVDT of each story.

Figure 6 
                  The model on the shaking table with the instrument.
Figure 6

The model on the shaking table with the instrument.

Table 2

Specifications and characteristics properties of the shaking table

Specifications Value
Weight of table (kg) −1,000
Max. payload (kg) 2,000
Max. displacement (mm) ±120
Max. velocity (m/s) 1.0
Max. acceleration (g) ∼1
Frequency range up to 20 Hz

3 Analysis of MDOF systems

3.1 Deterministic time-domain analysis

The Time-history analysis (THA) is a dynamic analytical technique in which structures can be linearly and nonlinearly analyzed. In this approach, the earthquake recording is a signal that varies in intensity over time. The complete dynamic equilibrium of MDOF systems can be defined by the following equation of motion [11,12,13]:

(2) M X ̈ ( t ) + C X ̇ ( t ) + KX ( t ) = M U ̈ g ( t ) ,

where M is the mass matrix of the structure, C is the damping matrix, K is the stiffness matrix, X is the relative response vector, and U ̈ g is the earthquake excitation vector. In order to make the MDOF system as a series of SDOF systems, Eq. (3) can be developed by superposing suitable amplitudes of the normal modes as follows:

(3) X ( x , t ) = i = 1 N ϕ i ( x ) u i ( t ) ,

where ϕ ( x ) is the mode-shape vector and u ( t ) is the modal amplitude. Substituting Eq. (3) in Eq. (2) yields the following:

(4) M ϕ u ̈ ( t ) + C ϕ u ̇ ( t ) + K ϕ u ( t ) = M { 1 } U ̈ g ( t ) .

To make the damping and stiffness matrices as a diagonal matrix, one can multiply Eq. (4) by ϕ T

(5) ϕ T M ϕ u ̈ ( t ) + ϕ T C ϕ u ̇ ( t ) + ϕ T K ϕ u ( t ) = ϕ T M { 1 } U ̈ g ( t ) .

Then, by using the orthogonality conditions [11] and dividing Eq. (5) by the generalized mass ( ϕ i T M ϕ i ), the following modal equation of motion may be expressed in an alternative form:

(6) u ̈ i ( t ) + 2 ξ i ω i u ̇ i ( t ) + ω i 2 u i ( t ) = ϕ i T M { 1 } U ̈ g ( t ) ,

where u i is an SDOF response which can be defined by using Duhamel’s integral [12] as follows:

(7) u i ( t ) = 0 t h i ( t τ ) F i ( τ ) d τ ,

where

(8) h i ( t τ ) = 1 ϕ i T M ϕ i ω D i e ξ i ω i ( t τ ) sin ω D i ( t τ ) ,

and

(9) ω D i = ω i 1 ξ 2 .

The uncoupled force can be defined in Eq. (10) as follows:

(10) F i ( τ ) = ϕ i T M { 1 } U ̈ g ( t ) .

In which, Eq. (11) represents the participation factor

(11) Γ i = ϕ i T M { 1 } ϕ i T M ϕ i .

Substituting Eq. (10) in Eq. (7) yields the following:

(12) u i ( t ) = Γ i ω D i 0 t e ξ i ω i ( t τ ) sin ω D i ( t τ ) U ̈ g ( t ) d τ .

Finally, the response of each story for all modes, X ( x , t ) , can be defined by substituting Eq. (12) in Eq. (3)

(13) X ( x , t ) = i = 1 N ϕ i ( x ) Γ i ω D i 0 t e ξ i ω i ( t τ ) sin ω D i ( t τ ) U ̈ g ( t ) d τ .

3.2 Stationary random vibration analysis (SRVA)

A statistical description of the loading is the only way to describe it because it is nondeterministic. To make this characterization possible, one must make several assumptions. It is important that the statistical qualities do not change over time, even while the excitation does. The Fourier transform can be used to convert the domain of the equation of motion of a MDOF system form time domain to frequency domain (Eq. (6)), as follows [11]:

(14) ω 2 u i ( ω ) + 2 i ξ i ω i ω u i ( ω ) + ω i 2 u i ( ω ) = Γ i U ̈ g ( ω ) ,

where u i ( ω ) is an SDOF response in the frequency domain when the system is subjected to random ground excitation. The response can be expressed as follows:

(15) u i ( ω ) = Γ i U ̈ ( ω ) ( ω i 2 ω 2 ) + ( 2 i ξ i ω i ω ) = H i ( ω ) Γ i U ̈ g ( ω ) ,

where H i ( ω ) is the transfer function (frequency response function) given as follows:

(16) H i ( ω ) = 1 ( ω i 2 ω 2 ) + ( 2 i ξ i ω i ω ) .

The total response for each floor can be written in Eq. (17).

(17) X i ( ω ) = i = 1 N ϕ i H i ( ω ) Γ i U ̈ g ( ω ) .

On the other hand, in order to represent the response as a PSD function in the frequency domain, the response can be written as follows:

(18) S XX ( ω ) = lim T 1 T | X i ( ω ) | 2 ,

where the notation < > denotes mathematical expectation of a value. Therefore, the PSD output will be

(19) S XX ( ω ) = i = 1 N j = 1 M ϕ i ϕ m T H i ( ω ) H j * ( ω ) Γ i Γ j S U ̈ U ̈ ( ω ) ,

where S U ̈ U ̈ ( ω ) is the PSD of the earthquake excitation which is defined in Eq. (21). Eq. (19) is known as the complete quadratic combination method. If the correlation between the parameters is eliminated, Eq. (19) can be rewritten as Eq. (20), and it is known as the square root of the sum of squares [1].

(20) S XX ( ω ) = p = 1 q | H structure ( ω ) | 2 Γ p 2 ϕ p ϕ p T S U ̈ U ̈ ( ω ) .

4 Modeling of earthquake excitation

4.1 Time domain model

Three earthquakes were used, with a change in their intensity, where the original earthquake was 0.32g as shown in (Figure 7), and it was reduced to 0.15g, and then it was reduced to 0.05g, to show what happened if the intensity of the earthquake changed.

Figure 7 
                  El-Centro Earthquake 0.32g without scale.
Figure 7

El-Centro Earthquake 0.32g without scale.

The acceleration recording is modeled through time modeling, and the original time is divided by the square root of the scaling factor. As for the acceleration, it remains the same value recording to Table 1. Figure 8 shows the shape of the earthquake after modeling it.

Figure 8 
                  Scale down El-Centro Earthquake 0.32, 0.15, and 0.05g.
Figure 8

Scale down El-Centro Earthquake 0.32, 0.15, and 0.05g.

4.2 PSD function model

The ground acceleration Kanai-Tajimi model has been widely employed in engineering structures under earthquake excitation analysis. A spectral density of the ground acceleration was idealized as a stationary randomness process [14,15] as defined in Eq. (21)

(21) S U ̈ U ̈ ( ω ) = ω 4 + ( 2 ξ g ω g ω ) 2 ( ω g 2 ω 2 ) 2 + ( 2 ξ g ω g ω ) 2 S o .

The three parameters, namely S o , ω g , and ξ g represent the broad-band excitation level at the base, the system’s natural frequency, and the damping to critical damping ratio, all normalized to one mass unit. The magnitude, frequency, and attenuation of seismic waves on the ground can all be taken into account while adjusting these parameters [14]. There are some difficulties with the Kanai-Tajimi model, and this problem appears in the low frequencies, especially in the displacement and velocity. A second filter, known as high pass filter function (HPFF), has been suggested to overcome the problem of low frequencies [11]. HPFF is necessary to correct possible drifting in the time of the first and second integral functions of U ̈ g ( t ) . Finally, Kanai-Tajimi double filter model can be expressed in Eq. (22) as follows [1]:

(22) S U ̈ U ̈ ( ω ) = 1 + 4 ξ g 2 ( ω / ω g ) 2 [ 1 ( ω / ω g ) 2 ] 2 + 4 ξ g 2 ( ω / ω g ) 2 × ( ω / ω f ) 4 [ 1 ( ω / ω f ) 2 ] 2 + 4 ξ g 2 ( ω / ω f ) 2 S o ,

where S o is the amplitude of the white-noise bedrock acceleration, ω g and ξ g are the frequency and damping ratio of the first filter related to the soil type, respectively; ω f and ξ f are the frequency and damping ratio of the second filter, respectively, which are applied to consider the ground acceleration. The double-filter function given in Eq. (22) has been used for ground acceleration. The optimal parameters, ω g = 15.6 rad / s , ξ g = 0.6 , ω f / ω g = 0.1 , and ξ f / ξ g = 1 , have been used, consistent with Kanai’s suggestion for firm soil conditions. The white-noise intensity S o for the ground acceleration has been adjusted to be comparable with the intensity of the north-south component of acceleration of the 1940 El Centro earthquake, Figure 9. In other words, the variance of El-Centro ground acceleration shown in Figure 10 is 0.3539 m 2 / s 4 (area under the PSD curve). And S o = 0.0078 m 2 / s 3 [16].

Figure 9 
                  Actual and theoretical PSD function of El Centro north-south component, 1940.
Figure 9

Actual and theoretical PSD function of El Centro north-south component, 1940.

Figure 10 
                  The three types of structures (parametric study).
Figure 10

The three types of structures (parametric study).

5 Numerical work

In this study, three types of structure as shown in Figure 10 are used as a parametric study as follows:

  1. Two-story steel structure with fixed support.

  2. Four-story steel structure with fixed support.

  3. Two-story L-shape steel structure (structure with irregularity in plan) with fixed support.

These three structures were modeled by using ABAQUS/standard 2019 software.

The behavior of the steel structures under dynamic loadings for both approaches, deterministic (THA) and nondeterministic (SRVA), can be simulated. The models consist of five parts which are column, beam, added mass, stiffeners, and base plate. The models were designed to be within the elastic range. The steel modulus of elasticity of E = 200,000 MPa, Poisson’s ratio of v = 0.3 , yield stress of 306 MPa, damping ratio ξ = 2 % (this study considers damping of all structures as constant damping), and a density of 7,850 kg/m3 were adopted as physical parameters. The solid element (C3D8R) 8-node linear brick, reduced integration, hourglass control was used to model the steel columns, beams, stiffeners, and the added mass [17]. The mesh size for columns, beams, and stiffeners is 12, 16, and 6 mm, respectively.

Two approaches were adopted in the analysis: deterministic dynamic modal analysis superposition method approach and dynamic SRVA. The predominant frequencies in both strong and weak axes for each structure are listed in Table 3. The corresponding mode shapes for the first and second predominant frequencies are shown in Figure 11.

Table 3

Predominant frequencies for the prototype in both strong and weak axes

Structure Mode Frequency in strong axis (Hz) Frequency in weak axis (Hz)
Two-story structure 1st 3.3072 2.3992
2nd 10.419 6.9846
Four-story structure 1st 1.6487 1.0906
2nd 5.2935 3.4295
3rd 9.5868 5.8523
4th 13.404 7.8814
Two-story L-shape structure 1st 3.0712 1.9225
2nd 9.4584 5.619
Figure 11 
               The first mode shape for all types of structures.
Figure 11

The first mode shape for all types of structures.

6 Results and discussion

After making the model and testing it on the shaking table and taking the results practically, the results were compared by modeling the model in the Abaqus/2019 program for the strong and weak directions as shown in Figures 13, 15 and 17 for the weak direction under three time histories 0.32, 0.15, and 0.05g, and Figures 12, 14 and 16 for the strong direction and under the same time histories. The dynamic response of the THA approach (time domain) of the model was obtained as shown in Figures 1217.

The building was analyzed on Abaqus/2019 by (SRVA) approach (frequency domain), the response was obtained as shown in Figures 1821 for strong direction and for weak direction (Table 4).

Table 4

Results of the RMS comparison between deterministic and nondeterministic methods

Structure Actual response Kanai-Tajimi (Theoretical response)
Variance of dis. (mm2) RMS of dis. (mm) Variance of dis. (mm2) RMS of dis. (mm)
F 1 F 2 F 1 F 2 F 1 F 2 F 1 F 2
Two-story/strong 5 . 4715 32 . 213 2 . 339 5 . 6756 10 . 673 63 . 0436 3 . 27 7 . 94
Two-story/weak 26 . 554 124 . 46 5 . 1532 11 . 1562 50 . 41 242 . 1136 7 . 1 15 . 56
Irregularity two-story 7 . 5963 38 . 737 2 . 756 6 . 224 15 . 887 81 . 18 3 . 986 9 . 01
Four-story 18 . 167 128 . 45 4 . 2623 11 . 33 31 . 95 227 5 . 652 15 . 066
F 3 F 4 F 3 F 4 F 3 F 4 F 3 F 4
302 . 2 456 . 45 17 . 384 21 . 364 535 . 43 810 23 . 14 28 . 46

After using three time-domain records and changing with different intensities (0.32, 0.15, and 0.05g), along weak direction (Figures 13, 15 and 17), it was noticed that the behavior of the response of the structure does not change significantly, but only the intensity of the response changes. This was also noticed for strong direction (Figures 12, 14 and 16). By comparing the response for strong and weak directions (Figures 1217), it was noticed that the response in both behavior and intensity changed significantly as the PSD function of the earthquake (shown in Figure 9) has different intensities (different energies) corresponding to the frequency content. SRVA approach can give a clear view on the effect of frequency content on the response as shown in Figures 1821. This means that the change in the natural frequency of the structure from one direction to another, as well as the intensity of the response because the energy distribution on the frequencies content in the earthquake, is not stationary with frequency domain.

Figure 12 
               Dynamic response of El-Centro 0.32g for 1st and 2nd floors in Z-direction.
Figure 12

Dynamic response of El-Centro 0.32g for 1st and 2nd floors in Z-direction.

Figure 13 
               Dynamic response of El-Centro 0.32g for 1st and 2nd floors in X-direction.
Figure 13

Dynamic response of El-Centro 0.32g for 1st and 2nd floors in X-direction.

Figure 14 
               Dynamic response of El-Centro 0.15g for 1st and 2nd floors in Z-direction.
Figure 14

Dynamic response of El-Centro 0.15g for 1st and 2nd floors in Z-direction.

Figure 15 
               Dynamic response of El-Centro 0.15g for 1st and 2nd floors in X-direction.
Figure 15

Dynamic response of El-Centro 0.15g for 1st and 2nd floors in X-direction.

Figure 16 
               Dynamic response of El-Centro 0.05g for 1st and 2nd floors in Z-direction.
Figure 16

Dynamic response of El-Centro 0.05g for 1st and 2nd floors in Z-direction.

Figure 17 
               Dynamic response of El-Centro 0.05g for 1st and 2nd floors in X-direction.
Figure 17

Dynamic response of El-Centro 0.05g for 1st and 2nd floors in X-direction.

Figure 18 
               PSD of displacement and acceleration for 1st and 2nd floors for 2-story structure.
Figure 18

PSD of displacement and acceleration for 1st and 2nd floors for 2-story structure.

Figure 19 
               PSD of displacement and acceleration for 1st and 2nd floors for 2-story structure.
Figure 19

PSD of displacement and acceleration for 1st and 2nd floors for 2-story structure.

Figure 20 
               PSD of displacement and acceleration for 1st and 2nd floors for irregular structure.
Figure 20

PSD of displacement and acceleration for 1st and 2nd floors for irregular structure.

Figure 21 
               PSD of displacement and acceleration for the 1st, 2nd, 3rd, and 4th floors.
Figure 21

PSD of displacement and acceleration for the 1st, 2nd, 3rd, and 4th floors.

7 Conclusion

In this study, a 1:6 scaled down model has been adopted to idealize a two-story steel building prototype. Three types of earthquakes were used to study their impact on the steel structure with different intensities. From the previous results:

  1. Analyzing structures in the frequency domain is more clear than in the time domain, giving an idea of which frequencies of the structure are involved in forming the response.

  2. Random vibration analysis transforms the stochastic phenomenon into a scalar function by stochastic model, and also gives the concept of energy distribution on the frequencies contained in the earthquake by PSD function, and thus gives clarification when designing buildings around the frequencies that dominate the area, in order to avoid them when designing.

  3. Changing the intensity of the earthquake does not affect the behavior of the response of the model, just the intensity of the response. Also, changing the natural frequency of the model affects the behavior of the model’s response.

  4. Due to different distribution of energy intensity on the frequency content in the earthquake, changing the natural frequency of the building from one direction to another will make the response of the structure differ in behavior as well as the intensity.

  5. The results showed that the deterministic approach may be a non-conservative approach.

Acknowledgments

We wish to express our gratitude to the Staff of the Structural Laboratory at the Department of Civil Engineering, University of Baghdad, for their valuable support.

  1. Funding information: The authors state no funding involved.

  2. Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.

  3. Conflict of interest: The authors state no conflict of interest.

References

[1] Rezayibana B. The effect of soil type on seismic response of tall telecommunication towers with random vibration analysis. Int J Eng. 2020 Mar 1;33(3):419–26.Search in Google Scholar

[2] Liu Z, Liu Z, Xu Y. Probability density evolution analysis of a shear-wall structure under stochastic ground motions by shaking table test. Soil Dyn Earthq Eng. 2019 Jul 1;122:53–66.Search in Google Scholar

[3] He ZC, Zhang Z, Li E. Multi-source random excitation identification for stochastic structures based on matrix perturbation and modified regularization method. Mech Syst Signal Process. 2019 Mar 15;119:266–92.Search in Google Scholar

[4] Al-Baghdadi H. Analysis of multiple-support excitation of long-span structures [thesis]. Iraq: University of Baghdad; 2002.Search in Google Scholar

[5] Li QS, Zhang YH, Wu JR, Lin JH. Seismic random vibration analysis of tall buildings. Eng Struct. 2004 Oct 1;26(12):1767–78.Search in Google Scholar

[6] Fei HE, Hongqiang LI, Jihong ZH, Zhongze GU. Structural topology optimization under stationary random base acceleration excitations. Chinese J Aeronaut. 2019 Jun 1;32(6):1416–27.Search in Google Scholar

[7] Al-Baghdadi H. Nonlinear dynamic response of reinforced concrete buildings to skew seismic structures [dissertation]. Iraq: University of Baghdad; 2014.Search in Google Scholar

[8] Jing J, Clifton GC, Roy K, Lim JB. Three-storey modular steel building with a novel slider device: Shake table tests on a scaled down model and numerical investigation. Thin-Walled Struct. 2020 Oct 1;155:106932.Search in Google Scholar

[9] AISC. Code of standard practice for steel buildings and bridges. ANSI/AISC 303-22. Chicago (IL), USA: American Institute of Steel Construction; 2016. p. 84.Search in Google Scholar

[10] Harris HG, Sabnis G. Structural modeling and experimental techniques. Boca Raton (FL), USA: CRC Press; 1999 Mar 30.Search in Google Scholar

[11] Clough RW, Penzien J. Dynamics of structures. 3rd ed. Berkeley (CA), USA: Computers & Structures, Inc; 2003. p. 752.Search in Google Scholar

[12] Mario P, Young HK. Structural dynamics: Theory and computation. 6th ed. Cham, Switzerland: Springer; 2019. p. 629.Search in Google Scholar

[13] Chopra AK. Dynamics of structures theory and applications to earthquake engineering. 4th ed. Upper Saddle River (NJ), USA: Pearson Education, Inc.; 2011.Search in Google Scholar

[14] Lin YK, Yong Y. Evolutionary Kanai-Tajimi earthquake models. J Eng Mech. 1987 Aug;113(8):1119–37.Search in Google Scholar

[15] Seya H, Talbott ME, Hwang HH. Probabilistic seismic analysis of a steel frame structure. Probabilistic Eng Mech. 1993 Jan 1;8(2):127–36.Search in Google Scholar

[16] Ravara A. Spectral analysis of seismic actions. Lisbon, Portugal: L.N.E.C.; 1965.Search in Google Scholar

[17] Abaqus/CAE, Abaqus 6.11 Abaqus/CAE User’s Manual; 2011.Search in Google Scholar

Received: 2022-04-23
Revised: 2022-08-22
Accepted: 2022-09-24
Published Online: 2023-07-03

© 2023 the author(s), published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 International License.

Articles in the same Issue

  1. Research Articles
  2. The mechanical properties of lightweight (volcanic pumice) concrete containing fibers with exposure to high temperatures
  3. Experimental investigation on the influence of partially stabilised nano-ZrO2 on the properties of prepared clay-based refractory mortar
  4. Investigation of cycloaliphatic amine-cured bisphenol-A epoxy resin under quenching treatment and the effect on its carbon fiber composite lamination strength
  5. Influence on compressive and tensile strength properties of fiber-reinforced concrete using polypropylene, jute, and coir fiber
  6. Estimation of uniaxial compressive and indirect tensile strengths of intact rock from Schmidt hammer rebound number
  7. Effect of calcined diatomaceous earth, polypropylene fiber, and glass fiber on the mechanical properties of ultra-high-performance fiber-reinforced concrete
  8. Analysis of the tensile and bending strengths of the joints of “Gigantochloa apus” bamboo composite laminated boards with epoxy resin matrix
  9. Performance analysis of subgrade in asphaltic rail track design and Indonesia’s existing ballasted track
  10. Utilization of hybrid fibers in different types of concrete and their activity
  11. Validated three-dimensional finite element modeling for static behavior of RC tapered columns
  12. Mechanical properties and durability of ultra-high-performance concrete with calcined diatomaceous earth as cement replacement
  13. Characterization of rutting resistance of warm-modified asphalt mixtures tested in a dynamic shear rheometer
  14. Microstructural characteristics and mechanical properties of rotary friction-welded dissimilar AISI 431 steel/AISI 1018 steel joints
  15. Wear performance analysis of B4C and graphene particles reinforced Al–Cu alloy based composites using Taguchi method
  16. Connective and magnetic effects in a curved wavy channel with nanoparticles under different waveforms
  17. Development of AHP-embedded Deng’s hybrid MCDM model in micro-EDM using carbon-coated electrode
  18. Characterization of wear and fatigue behavior of aluminum piston alloy using alumina nanoparticles
  19. Evaluation of mechanical properties of fiber-reinforced syntactic foam thermoset composites: A robust artificial intelligence modeling approach for improved accuracy with little datasets
  20. Assessment of the beam configuration effects on designed beam–column connection structures using FE methodology based on experimental benchmarking
  21. Influence of graphene coating in electrical discharge machining with an aluminum electrode
  22. A novel fiberglass-reinforced polyurethane elastomer as the core sandwich material of the ship–plate system
  23. Seismic monitoring of strength in stabilized foundations by P-wave reflection and downhole geophysical logging for drill borehole core
  24. Blood flow analysis in narrow channel with activation energy and nonlinear thermal radiation
  25. Investigation of machining characterization of solar material on WEDM process through response surface methodology
  26. High-temperature oxidation and hot corrosion behavior of the Inconel 738LC coating with and without Al2O3-CNTs
  27. Influence of flexoelectric effect on the bending rigidity of a Timoshenko graphene-reinforced nanorod
  28. An analysis of longitudinal residual stresses in EN AW-5083 alloy strips as a function of cold-rolling process parameters
  29. Assessment of the OTEC cold water pipe design under bending loading: A benchmarking and parametric study using finite element approach
  30. A theoretical study of mechanical source in a hygrothermoelastic medium with an overlying non-viscous fluid
  31. An atomistic study on the strain rate and temperature dependences of the plastic deformation Cu–Au core–shell nanowires: On the role of dislocations
  32. Effect of lightweight expanded clay aggregate as partial replacement of coarse aggregate on the mechanical properties of fire-exposed concrete
  33. Utilization of nanoparticles and waste materials in cement mortars
  34. Investigation of the ability of steel plate shear walls against designed cyclic loadings: Benchmarking and parametric study
  35. Effect of truck and train loading on permanent deformation and fatigue cracking behavior of asphalt concrete in flexible pavement highway and asphaltic overlayment track
  36. The impact of zirconia nanoparticles on the mechanical characteristics of 7075 aluminum alloy
  37. Investigation of the performance of integrated intelligent models to predict the roughness of Ti6Al4V end-milled surface with uncoated cutting tool
  38. Low-temperature relaxation of various samarium phosphate glasses
  39. Disposal of demolished waste as partial fine aggregate replacement in roller-compacted concrete
  40. Review Articles
  41. Assessment of eggshell-based material as a green-composite filler: Project milestones and future potential as an engineering material
  42. Effect of post-processing treatments on mechanical performance of cold spray coating – an overview
  43. Internal curing of ultra-high-performance concrete: A comprehensive overview
  44. Special Issue: Sustainability and Development in Civil Engineering - Part II
  45. Behavior of circular skirted footing on gypseous soil subjected to water infiltration
  46. Numerical analysis of slopes treated by nano-materials
  47. Soil–water characteristic curve of unsaturated collapsible soils
  48. A new sand raining technique to reconstitute large sand specimens
  49. Groundwater flow modeling and hydraulic assessment of Al-Ruhbah region, Iraq
  50. Proposing an inflatable rubber dam on the Tidal Shatt Al-Arab River, Southern Iraq
  51. Sustainable high-strength lightweight concrete with pumice stone and sugar molasses
  52. Transient response and performance of prestressed concrete deep T-beams with large web openings under impact loading
  53. Shear transfer strength estimation of concrete elements using generalized artificial neural network models
  54. Simulation and assessment of water supply network for specified districts at Najaf Governorate
  55. Comparison between cement and chemically improved sandy soil by column models using low-pressure injection laboratory setup
  56. Alteration of physicochemical properties of tap water passing through different intensities of magnetic field
  57. Numerical analysis of reinforced concrete beams subjected to impact loads
  58. The peristaltic flow for Carreau fluid through an elastic channel
  59. Efficiency of CFRP torsional strengthening technique for L-shaped spandrel reinforced concrete beams
  60. Numerical modeling of connected piled raft foundation under seismic loading in layered soils
  61. Predicting the performance of retaining structure under seismic loads by PLAXIS software
  62. Effect of surcharge load location on the behavior of cantilever retaining wall
  63. Shear strength behavior of organic soils treated with fly ash and fly ash-based geopolymer
  64. Dynamic response of a two-story steel structure subjected to earthquake excitation by using deterministic and nondeterministic approaches
  65. Nonlinear-finite-element analysis of reactive powder concrete columns subjected to eccentric compressive load
  66. An experimental study of the effect of lateral static load on cyclic response of pile group in sandy soil
Downloaded on 12.9.2025 from https://www.degruyterbrill.com/document/doi/10.1515/jmbm-2022-0261/html
Scroll to top button