Locate Damage Based on Change in Structural Shape Calculated From Uniform Load Surface

Reticulated shell structures have been widely built for public assembly venues, where many people get together during events. Therefore, it is important to conduct condition assessment for this type of structure to ensure the safety of the general public. Considering that the member configuration of this type of structure may follow a regular pattern and damage in a local region may destroy the regular pattern, a damage detection approach based on the change in structural shape is proposed in this study. The change in structural shape can be obtained from the displacement at each joint. Since it may be difficult to measure displacements on this type of structure, it is proposed to use the uniform load surface calculated from the constructed modal flexibility matrix to represent displacements at joints. Therefore, this approach requires the measurement of acceleration responses, instead of displacement measurement. For validating the feasibility of the proposed approach, numerical simulations are conducted on a single-layer dome structure with different levels of damage severity considered. The obtained results verify that the proposed approach is capable of locating damage to exact members.

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Damage localization using shape change in uniform load surface for civil large-span space structures

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x18806388 ◽

2018 ◽

Vol 30 (9) ◽

pp. 1339-1354

Author(s):

Guirong Yan ◽

Tiantian Li ◽

Jianxin Yu ◽

Ruoqiang Feng ◽

Xiaoyun Shao

Keyword(s):

Shape Change ◽

Single Layer ◽

Mode Shapes ◽

Space Structures ◽

Damage Localization ◽

Regular Pattern ◽

Uniform Load ◽

Structural Shape ◽

Large Span ◽

Load Surface

Civil large-span space structures have been widely built for public assembly venues. The failure of this type of structure may endanger the lives of many people. Considering that the member configuration of this type of structure may follow a regular pattern and damage in a local region may destroy the regular pattern, a damage detection approach based on the change in structural shape has been proposed by the present authors. In that approach, to obtain the change in structural shape due to damage, the displacements at joints between members are required to be measured. Since it is difficult to measure displacements on this type of structure in practice, in this study, the authors proposed to use the shape change of the uniform load surface for damage localization. Uniform load surface physically represents the deflection profile of the structure under the assumed uniformly distributed loading and can be calculated from the flexibility matrix constructed from the identified natural frequencies and mode shapes. This approach can locate damage to exact structural members. It will avoid costly and tedious work in measuring displacements. This approach has been numerically validated on single-layer space structures with two different member configurations.

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A Novel Two-Stage Structural Damage Identification Method Based on Superposition of Modal Flexibility Curvature and Whale Optimization Algorithm

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455421501698 ◽

2021 ◽

pp. 2150169

Author(s):

Minshui Huang ◽

Xihao Cheng ◽

Zhigang Zhu ◽

Jin Luo ◽

Jianfeng Gu

Keyword(s):

Optimization Algorithm ◽

Damage Identification ◽

Whale Optimization Algorithm ◽

Two Stage ◽

Simply Supported ◽

Damage Location ◽

Flexibility Matrix ◽

Modal Flexibility ◽

Whale Optimization ◽

The Impact

A novel two-stage method is proposed to properly identify the location and severity of damage in plate structures. In the first stage, a superposition of modal flexibility curvature (SMFC) is adopted to locate the damage accurately, and the identification index of modal flexibility matrix is improved. The low-order modal parameters are used and a new column matrix is formed based on the modal flexibility matrix before and after the structure is damaged. The difference of modal flexibility matrix is obtained, which is used as a damage identification index. Meanwhile, based on SMFC, a method of weakening the “vicinity effect” is proposed to eliminate the impact of the surrounding elements to the damaged elements when damage identification is carried out for the plate-type structure. In the second stage, the objective function based on the flexibility matrix is constructed, and according to the damage location identified in the first stage, the actual damage severity is determined by the enhanced whale optimization algorithm (EWOA). In addition, the effects of 3% and 10% noise on damage location and severity estimation are also studied. By taking a simply supported beam and a four-side simply supported plate as examples, the results show that the method can accurately estimate the damage location and quantify the damage severity without noise. When considering noise, the increase of noise level will not affect the assessment of damage location, but the error of quantifying damage severity will increase. In addition, damage identification of a steel-concrete composite bridge (I-40 Bridge) under four damage cases is carried out, and the results show that the modified method can evaluate the damage location and quantify 5%–92% of the damage severity.

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FEM Free Damage Detection of Beam Structures Using the Deflections Estimated by Modal Flexibility Matrix

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455421501285 ◽

2021 ◽

pp. 2150128

Author(s):

Wen-Yu He ◽

Wei-Xin Ren ◽

Lei Cao ◽

Quan Wang

Keyword(s):

Damage Detection ◽

Structural Damage ◽

Damage Index ◽

Element Model ◽

Mode Shapes ◽

Beam Structures ◽

Flexibility Matrix ◽

Damage Quantification ◽

Modal Flexibility ◽

The Cost

The deflection of the beam estimated from modal flexibility matrix (MFM) indirectly is used in structural damage detection due to the fact that deflection is less sensitive to experimental noise than the element in MFM. However, the requirement for mass-normalized mode shapes (MMSs) with a high spatial resolution and the difficulty in damage quantification restricts the practicability of MFM-based deflection damage detection. A damage detection method using the deflections estimated from MFM is proposed for beam structures. The MMSs of beams are identified by using a parked vehicle. The MFM is then formulated to estimate the positive-bending-inspection-load (PBIL) caused deflection. The change of deflection curvature (CDC) is defined as a damage index to localize damage. The relationship between the damage severity and the deflection curvatures is further investigated and a damage quantification approach is proposed accordingly. Numerical and experimental examples indicated that the presented approach can detect damages with adequate accuracy at the cost of limited number of sensors. No finite element model (FEM) is required during the whole detection process.

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Analysis of Nonlinear Buckling of a Long-Span Elliptic Paraboloid Suspended Dome Structure

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.639-640.191 ◽

2013 ◽

Vol 639-640 ◽

pp. 191-197 ◽

Cited By ~ 3

Author(s):

Zheng Rong Jiang ◽

Kai Rong Shi ◽

Xiao Nan Gao ◽

Qing Jun Chen

Keyword(s):

Single Layer ◽

Buckling Mode ◽

Nonlinear Buckling ◽

Elliptic Paraboloid ◽

Geometric Imperfection ◽

Long Span ◽

Initial Geometric Imperfection ◽

Dome Structure ◽

Unsymmetrical Loading ◽

The Stability

The suspended dome structure, which is a new kind of hybrid spatial one composed of the upper single layer latticed shell and the lower cable-strut system, generally has smaller rise-to-span ratio, thus the overall stability is one of the key factors to the design of the structure. The nonlinear buckling behavior of an elliptic paraboloid suspended dome structure of span 110m80m is investigated by introducing geometric nonlinearity, initial geometric imperfection, material elastic-plasticity and half-span distribution of live loads. The study shows that the coefficient of stable bearing capacity usually is not minimal when the initial geometric imperfection configuration is taken as the first order buckling mode. The unsymmetrical loading distribution and the material nonlinearity might have significant effects on the coefficient. The structure is sensitive to the changes of initial geometric imperfection, and the consistent mode imperfection method is not fully applicable to the stability analysis of suspended dome structure.

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Damage Identification of Plate Structure Based on the Method of Modal Flexibility Curvature Difference

MATEC Web of Conferences ◽

10.1051/matecconf/201925602015 ◽

2019 ◽

Vol 256 ◽

pp. 02015

Author(s):

Jiangang Zhao ◽

Yuxiang Zhang ◽

Jiazhao Chen

Keyword(s):

Numerical Analysis ◽

Lower Order ◽

Damage Identification ◽

Higher Order ◽

Plate Structure ◽

First Order ◽

Flexibility Matrix ◽

Damage Degree ◽

Higher Order Modes ◽

Modal Flexibility

According to the higher order modes of the structure are difficult to extract and the lower order are easy to obtain in practice, it is put forward that only uses the parameters of lower or first-order modal to constitute the modal flexibility curvature difference (MFCD) as the index of damage identification, which based on the flexibility matrix of structure being sensitive to the structure modal characteristics. Numerical analysis is made on different damage conditions of a plate structure, and the result shows that the MFCD can not only accurately identify the single-damage and multi-damage position of plate structure, but also reflect the size of damage degree. It has a great significance to apply the index into the range of damage identification of actual structures.

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XBLOC-PLUS â€“ DEVELOPMENT OF A REGULAR PLACED INTERLOCKING ARMOUR UNIT

Coastal Engineering Proceedings ◽

10.9753/icce.v36.structures.45 ◽

2018 ◽

pp. 45

Author(s):

Robert Jacobs ◽

Pieter Bakker ◽

Ineke Vos-Rovers ◽

Bas Reedijk

Keyword(s):

Single Layer ◽

Regular Pattern ◽

Random Orientation ◽

Individual Unit ◽

Block Placement ◽

Cost Efficient ◽

Efficient Option ◽

Regular Placement

Randomly placed single layer interlocking concrete armor units are currently the most advanced and cost-efficient option for the protection of breakwaters. The key feature of these units is the random orientation of the units, which requires the crane operator to assess the orientation of each individual unit during block placement. DMC noticed the desire for a block which can be placed in a regular pattern as this will increase the placement rates. Apart of this, regular placement of armor units can also be preferred for aesthetical reasons. Fifteen years after the introduction of Xbloc, DMC therefore introduces a new breakwater armour unit called XblocPlus which is placed with uniform block orientations.

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Improved Damage Detection for Beam-type Structures using a Uniform Load Surface

Structural Health Monitoring ◽

10.1177/1475921706072062 ◽

2007 ◽

Vol 6 (2) ◽

pp. 99-110 ◽

Cited By ~ 56

Author(s):

Jialai Wang ◽

Pizhong Qiao

Keyword(s):

Damage Detection ◽

Uniform Load ◽

Beam Type ◽

Load Surface

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Advances in Application and Research of Suspendome Structures

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.243-249.920 ◽

2011 ◽

Vol 243-249 ◽

pp. 920-928

Author(s):

Kai Rong Shi ◽

Yi Liang Zhang ◽

Long Wang

Keyword(s):

Shell Structure ◽

Single Layer ◽

Structural System ◽

Engineering Applications ◽

Research Status ◽

New Type ◽

Dome Structure ◽

Research Orientations ◽

Cable Dome ◽

Application Prospects

The suspendome structure is a new-type of hybrid prestressed spatial structural system which has been developing on the basis of single-layer latticed shell structure and cable dome structure. The wide application prospects of this type of structure have been presented initially since its emergence around ten years ago. Several representative engineering applications of suspendome structures are introduced, and the research status of this structure at home and abroad is summarized. Moreover, further research orientations of suspendome structures are discussed and prospected.

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Infographical modeling of multicomponent systems

Services in Russia and abroad ◽

10.12737/4867 ◽

2014 ◽

Vol 8 (4) ◽

pp. 217-232

Author(s):

Виталий Чулков ◽

Vitaliy Chulkov ◽

Николай Комаров ◽

Nikolay Komarov ◽

Исраиль Левин ◽

...

Keyword(s):

Sewage Treatment ◽

Single Layer ◽

Practical Application ◽

Local Conditions ◽

Special Software ◽

Analysis Of Dynamics ◽

Further Development ◽

Previous Phase ◽

Different Levels

Modeling of functioning of systems in infographics allows to consider ojects under investigation at different levels of their complexity, with an important aspect being the qualimetrical assessment of quality of functioning of various systems. Multidimensional scaling found reflection in use of single-layer and multilayered polar systems of coordinates. The composite model displays the dynamics of change of local conditions of process of convergence of norms at the end of each previous phase of process. Examples of practical application of infographic models by producers of vodka products and models for an assessment of parameters of sewage treatment in housing and communal services are reviewed. Similar models gained further development as instruments of management of competitiveness thanks to the development of special software which allows to automate the process of their construction and the analysis of dynamics of occurring changes of controlled parameters.

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