Substructure Pseudo-dynamic Tests Research Articles

Substructure Pseudo-Dynamic Test Study for a Structure Including Soil–Pile–Structure Dynamic Interaction

An improved Penzien model is proposed in this paper as a simplified model of soil–pile–structure interaction. The dynamic nonlinearity of soil under earthquake excitation is simulated by ANSYS in a free-field model and added to the original Penzien model. The improved Penzien model uses the finite element software ANSYS 2021 to simulate the dynamic nonlinearity of soil. The improved Penzien model is then used as a simplified calculation model of the numerical substructure. A substructure pseudo-dynamic test based on the improved Penzien model is carried out. The realization of the substructure pseudo-dynamic test verifies the feasibility and effectiveness of this method, which provides a convenient test method for the study of soil–pile–structure interaction in general laboratories. Soil and structure interaction reduces the acceleration of the structure, and the response exhibited a hysteresis phenomenon because of the nonlinear characteristics of the soil. The influences of soil–pile–structure interaction on velocity and displacement are very complex. The conclusions are reasonable, which proves that the substructure pseudo-dynamic test method of soil–pile–structure dynamic interaction using the improved Penzien model is feasible.

Substructure hybrid test examining the seismic response of point-supported glass façades attached to large-span spatial steel structures

Point-supported glass façade (PSGF) is one of the most widely used types of non-structural components. Its earthquake damage may not only cause economic loss, but also interruption of building use and even casualties. This paper aims at investigating the seismic response of the large-span spatial structure and PSGF coupling system through the substructure hybrid test. The substructure pseudo-dynamic (PSD) test method is used, that is, the loading rate of the test is slow as that of the quasi-static tests. The finding is that when the glass panel begins to fail, the cracks occur and instantly spread to the whole glass panel along the diagonal direction due to the stress concentration at a bolt hole of double-layer laminated glass, accompanied by looseness of several point-fixed fitting screws. The drift angle of one glass panel is about 50.0%–81.9% of that of glass façade δ in the critical and failure state, indicating that the supporting system can reduce the in-plane deformation of the glass panel. And the glass façade can reduce the acceleration responses of the mid-span upper chord nodes of the large-span spatial structure by 4.74%–13.98%. Finally, the seismic performance evaluation indexes of PSGF are determined based on the drift angle δ and percentage of damaged glass panels for the slight, moderate, and extensive limit states. It will provide an example and reference for the seismic performance evaluation of the PSGF.

A pseudodynamic testing algorithm for obtaining seismic responses of structures

A new family method is proposed for pseudodynamic tests. This family method can integrate favourable numerical properties together, such as the unconditional stability, explicit formulation, second-order accuracy and favourable numerical dissipation. Since the proposed family method can generally have an explicit formulation of each time step its pseudodynamic implementation involves no iteration procedure. Hence, the pseudodynamic tests can be easily conducted when compared to an implicit pseudodynamic method, where an iteration procedure must be involved for each time step. On the other hand, the properties of unconditional stability, second order accuracy and numerical dissipation indicate that the proposed pseudodynamic algorithm is promising for solving inertial problems, where the total response is dominated by low frequency modes and the high frequency responses are of no interest. The unconditional stability implies that there is no limitation on step size for the high frequency modes. Besides, the dominated low frequency modes can be reliably integrated by choosing an appropriate time step since the proposed family method can have a second order accuracy. Finally, the spurious growth of high frequency responses can be suppressed or filtered out by the desired numerical dissipation. As a result, the proposed pseudodynamic algorithm is very promising for a general pseudodynamic test or a substructure pseudodynamic test.

Feasibility of Substructure Pseudo Dynamic Test on the Tanks in Seismic Research

Modern structures tend to be more and more complicated, setting up the complete calculation model and getting each part of the dynamic response is almost impossible and unnecessary. The substructure analysis technology is effective for the dynamic analysis of large and complex structure. The substructure theory has become increasingly mature and perfect, and has been widely used in structural analysis and calculation. This article simply introduces the principle of substructure pseudo dynamic test, and using the finite element software—ADINA simulates a steel frame.

Earthquake response analysis of high-parformance buckling restrained braces by using substructure pseudodynamic test

Earthquake response analysis of high-parformance buckling restrained braces by using substructure pseudodynamic test

Substructure Pseudo-Dynamic Testing of a Full-Scale Confined Masonry Building

The seismic behavior of a single-story ten-bay confined masonry structure was investigated using substructure pseudo-dynamic tests. Only one bay of the prototype was regarded as the test model and the remainder was regarded as numerical model. The test results show that the test model withstood, with slight damage, strong earthquakes with peak ground acceleration of 1600 gal. It is found that prototypes of the tested type exhibited satisfactory seismic performance. Hence, the confinement can be reduced if the budget of the building is limited.

PSEUDO-DYNAMIC RESPONSE TESTS ON SELF-RETURNING JOINT MECHANISM USING Ni-Ti-Co ALLOY

This paper deals with a beam-to-column connection using mechanical fasteners made of shape memory alloy, abbreviated as 'SMA bolt' hereafter. A flush-type endplate connection at beam-ends is arranged by use of SMA bolts, and the connection works as a super-elastic joint mechanism. This paper describes sub-structure pseudo-dynamic response tests on a super-elastic frame system with fictitious tension-bar diagonal braces. For the comparison, a similar structural system bolted by ordinary mild-steel bolts is also tested pseudo-dynamically. It was observed that the SMA bolt system returned to its original position, while the ordinary bolt system showed some permanent set after earthquakes. Additionally, response analysis based on a nonlinear-elastic model and a slip model is performed and compared with the test results.

Post-earthquake capacity evaluation of R/C buildings based on pseudo-dynamic tests

In this paper, post-earthquake capacity evaluation method of reinforced concrete buildings was studied. Substructure pseudo-dynamic test and static loading test of first story column in a four-story R/C building was carried out in order to investigate the validity of the evaluation method proposed in the Damage Assessment Guideline (JBDPA 2001). In pseudo-dynamic test, different levels of damage were induced in the specimens by pre-loading, and input levels of seismic motion, at which the specimens reached to the ultimate stage, were examined. From the experimental result, no significant difference in damage levels such as residual crack width between the specimens under static and pseudo-dynamic loading was found. It is shown that the seismic capacity reduction factors <TEX>${\eta}$</TEX> can provide a reasonable estimation of post-earthquake seismic capacity of R/C buildings suffered earthquakes.

Sub-Structure Pseudo-Dynamic Response Test of a Pseudo-Elastic Bracing System Made of Shape Memory Alloy

This paper deals with shape memory alloy. As a first step to assess the applicability of this kind of alloy in a structural system, a tension bar made of this kind of alloy that exhibits pseudo-elasticity at room temperature is used herein as a passive bracing system. This paper describes sub-structure pseudo-dynamic tests on pseudo-elastic bracing system with hysteretic damper. A pseudo-elastic bracing system is better to be used with other hysteretic elements such as a hysteretic damper. A damper provides energy dissipation within small displacement levels, and a pseudo-elastic bracing system works in turn as a back-up/fail-safe system when an accidental failure of damper or damper interface occurs, and also it helps to pull back the structure to the original position by uninstalling the damper after earthquake.

Plasticity‐fibre model for steel triangular plate energy dissipating devices

AbstractProperly fabricated triangular‐plate added damping and stiffness (TADAS) devices can sustain a large number of yield reversals without strength degradation, thereby dissipating a significant amount of earthquake‐induced energy. A pronounced isotropic‐hardening effect is recognized in the force‐deformation relationships of the TADAS devices made from two grades of low yield strength steel. The proposed plasticity‐fibre model employing two surfaces (a yield surface and a bounding surface) in plasticity theory accurately predicts the experimental responses of the TADAS devices. This model is also implemented into a computer program DRAIN2D+ to investigate a frame response with the TADAS devices. Substructure pseudo‐dynamic tests and analytical studies of a two‐storey steel frame constructed with the low yield strength steel, LYP‐100 or LYP‐235 grade, TADAS devices confirm that the dynamic structural response can only be predicted if the proposed plasticity‐fibre model is used for LYP‐100 steel TADAS device. Copyright © 2002 John Wiley &amp; Sons, Ltd.

実験誤差制御機能を有したサブストラクチャ仮動的実験のための数値積分法

Proposed is a new integration method that can ensure unconditional stability and control the growth of experimental errors in the substructure pseudo dynamic test. This method, referred to as a-OS method, is an extension of OS method that has already been proposed and includes an additional integration parameter. This parameter is the source of numerical dissipation, which in turn makes the growth of experimental errors suppressed. Stability and accuracy characteristics of the method are quantified analytically, and effectiveness of this method is demonstrated by numerical experimentation.

サブストラクチャ仮動的実験のための数値積分法 : サブストラクチャ法を用いた仮動的実験の開発

As part of a comprehensive study on developing the pseudo dynamic test using substructuring techniques, this paper proposes new integration techniques effective to the substructure pseudo dynamic test. First, conditions that the substructure pseudo dynamic test should fulfill in order to ensure accurate responses were identified. Second, various integration methods were surveyed with respect to their applicability to the substructure pseudo dynamic test, and based on the survey, algorithms using mixed integration methods and the operator-splitting (OS) method were proposed. Stability and accuracy of the algorithm using the OS method was examined analytically, and it was proven that this algorithm is perfectly adaptable to the substructure pseudo dynamic test and can provide unconditionally stable responses. Criteria for estimating the accuracy of this algorithm were also presented. Finally, effectiveness of this algorithm was calibrated for a structure with 20 degrees and a 3 story structure with base isolation devices, and advantages of the proposed algorithm over conventional integration procedures were demonstrated.