Actual Effects of Local Buckling of Thin-Walled Metal Roof Decking: Control Experimental Verification Performed during Structure Realization

2013 ◽  
Vol 368-370 ◽  
pp. 1503-1506
Author(s):  
Marcela Karmazínová ◽  
Jindrich Melcher
Keyword(s):  
Experimental Verification ◽  
Carrying Capacity ◽  
Failure Process ◽  
Local Buckling ◽  
Load Carrying Capacity ◽  
Limit States ◽  
Loading Test ◽  
Actual Behaviour ◽  
Load Carrying ◽  
Thin Walled

Experimental verification of structural members can be the necessary part of the structural design of load-carrying civil structures, mainly in the period of last two decades. In some cases, the knowledge obtained from the tests is the sole source of the reliable information about actual behaviour of structural member in strain and failure process and about its objective load-carrying capacity. The paper is specifically aimed at the control experimental verification of roof decking based on thin-walled metal profiled sheets. Loading test has been performed during structure erection, as additional resource for the verification of actual behaviour and objective load-carrying capacity and for the confirmation or refinement of static design assumptions and results, within the ultimate and serviceability limit states. The subject of the control experimental verification was roof decking composed of thin-walled metal cassettes with thermal insulation at its upper side, used for the university lecture room roofing.

scholarly journals Eigenproblem Versus the Load-Carrying Capacity of Hybrid Thin-Walled Columns with Open Cross-Sections in the Elastic Range

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3468
Author(s):  
Zbigniew Kolakowski ◽  
Andrzej Teter
Keyword(s):  
Cross Sections ◽  
Carrying Capacity ◽  
Ultimate Load ◽  
Equilibrium Path ◽  
Load Carrying Capacity ◽  
Nonlinear Buckling ◽  
Elastic Range ◽  
Load Carrying ◽  
Thin Walled ◽  
Ultimate Load Carrying Capacity

The phenomena that occur during compression of hybrid thin-walled columns with open cross-sections in the elastic range are discussed. Nonlinear buckling problems were solved within Koiter’s approximation theory. A multimodal approach was assumed to investigate an effect of symmetrical and anti-symmetrical buckling modes on the ultimate load-carrying capacity. Detailed simulations were carried out for freely supported columns with a C-section and a top-hat type section of medium lengths. The columns under analysis were made of two layers of isotropic materials characterized by various mechanical properties. The results attained were verified with the finite element method (FEM). The boundary conditions applied in the FEM allowed us to confirm the eigensolutions obtained within Koiter’s theory with very high accuracy. Nonlinear solutions comply within these two approaches for low and medium overloads. To trace the correctness of the solutions, the Riks algorithm, which allows for investigating unsteady paths, was used in the FEM. The results for the ultimate load-carrying capacity obtained within the FEM are higher than those attained with Koiter’s approximation method, but the leap takes place on the identical equilibrium path as the one determined from Koiter’s theory.

Flexural strengthening of pre-cracked RC slabs with prestressed NSM CFRP laminates and evaluation of strain loss

2021 ◽  
pp. 136943322110105
Author(s):  
M.R. Mostakhdemin Hosseini ◽  
Salvador J.E. Dias ◽  
Joaquim A.O. Barros
Keyword(s):  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Limit States ◽  
Transfer Length ◽  
Rc Structures ◽  
Cracked Concrete ◽  
Flexural Strengthening ◽  
Cfrp Laminates ◽  
Load Carrying ◽  
Rc Slabs

The strengthening intervention of RC structures often involves already cracked concrete. To evaluate the effect of the level of damage prior to the strengthening (pre-cracks) on the behavior of the flexurally strengthened RC slabs with prestressed NSM CFRP laminates, an experimental research was carried out. Two pre-cracking levels of damage were analyzed and, for each one, three levels of prestress were tested (0%, 20% and 40%). The obtained results showed that the strengthening of damaged RC slabs with prestressed NSM CFRP laminates results in a significant increase on the load carrying capacity at serviceability limit states. Pre-cracked RC slabs strengthened with prestressed NSM CFRP laminates presented a load carrying capacity almost similar to the corresponding uncracked strengthened slabs. To determine the effective prestress level in CFRP laminates, the variation of strain over the length of the CFRP and over time was experimentally recorded. The prestress transfer length was also evaluated. The experimental results revealed that the transfer length of CFRP laminates was less than 150 mm, and the maximum value of strain loss out of transfer length (around 14%) was measured close to the cracked section of the damaged RC slabs. Significant part of strain loss in CFRP laminates occurred during 24 h after releasing the prestress load.

Reliability analysis of wood I-joists

1993 ◽  
Vol 20 (4) ◽  
pp. 564-573 ◽  
Author(s):  
R. O. Foschi ◽  
F. Z. Yao
Keyword(s):  
Reliability Analysis ◽  
Carrying Capacity ◽  
Failure Modes ◽  
Limit State ◽  
Load Carrying Capacity ◽  
Limit States ◽  
Element Analysis ◽  
Strength Limit ◽  
Reliability Method ◽  
Load Carrying

This paper presents a reliability analysis of wood I-joists for both strength and serviceability limit states. Results are obtained from a finite element analysis coupled with a first-order reliability method. For the strength limit state of load-carrying capacity, multiple failure modes are considered, each involving the interaction of several random variables. Good agreement is achieved between the test results and the theoretical prediction of variability in load-carrying capacity. Finally, a procedure is given to obtain load-sharing adjustment factors applicable to repetitive member systems such as floors and flat roofs. Key words: reliability, limit state design, wood composites, I-joist, structural analysis.

STABILITY PROBLEMS OF STEEL‐CONCRETE MEMBERS COMPOSED OF HIGH‐STRENGTH MATERIALS

2010 ◽  
Vol 16 (3) ◽  
pp. 352-362 ◽  
Author(s):  
Zdeněk Kala ◽  
Libor Puklický ◽  
Abayomi Omishore ◽  
Marcela Karmazínová ◽  
Jindřich Melcher
Keyword(s):  
Theoretical Analysis ◽  
Experimental Research ◽  
Carrying Capacity ◽  
High Strength ◽  
Statistical Characteristics ◽  
Load Carrying Capacity ◽  
Limit States ◽  
Load Carrying ◽  
Geometrical Imperfections

The presented paper deals with the stochastic analysis of the ultimate limit states of steel‐concrete building members. The load carrying capacity of steel‐concrete columns, comprising of steel profiles encased in high strength concrete, in compression is analyzed. The first part of the paper lists assumptions for the determination of the theoretical load carrying capacity of the column. Principles of elasticity and plasticity are used to determine stresses in the concrete and steel sections. Statistical characteristics of input material and geometrical imperfections are listed. Results of the theoretical analysis are then compared with results of experimental research. Statistical characteristics of obtained results of the theoretical analysis were verified using statistical characteristics obtained from experimental research. Numerical simulation LHS and Monte Carlo methods, which take into account the influences of variability of input imperfections, were employed. The influence of the utilization of the plastic reserve in the determination of the load carrying capacity of the analysed strut is shown. The influence of the initial geometric imperfections of initial strut curvature on the load carrying capacity is also presented. Santrauka Straipsnyje pateikta plienbetonio pastatu elementu didžiausiu ribiniu būkliu stochastine analize, analizuojama plienbetonio kolonu, sudarytu iš plieniniu profiliuočiu, padengtu didelio stiprio betonu, laikomoji galia gniuždant. Pirmoje straipsnio dalyje išvardytos kolonos teorines laikomosios galios nustatymo prielaidos. Tamprumo ir plastiškumo principai taikyti itempiams betono ir plieno skerspjūviuose nustatyti. Nustatytos medžiagu ir geometriniu defektu statistines charakteristikos, teorines analizes rezultatai palyginti su eksperimentiniu tyrimu rezultatais. Teorines analizes metu gautu rezultatu statistines charakteristikos patikrintos taikant iš eksperimentiniu tyrimu gautus statistinius rodiklius. Pritaikytas skaitinis modeliavimas LHS ir Monte Karlo metodais, kurie ivertina pradiniu defektu kintamumo itaka. Parodyta plastiškumo atsargos naudojimo itaka, nustatant analizuojamojo statramsčio laikomaja galia, pateikta pradinio statramsčio išlinkio pirminiu geometriniu defektu itaka laikomajai galiai.

Geometric Imperfection Sensitivity and Effect of Constraint Conditions of H-Section Columns under Compression

2010 ◽  
Vol 102-104 ◽  
pp. 140-144
Author(s):  
Yi Ping Wang ◽  
Yong Zang ◽  
Di Ping Wu
Keyword(s):  
Carrying Capacity ◽  
Steel Structures ◽  
Load Carrying Capacity ◽  
Imperfection Sensitivity ◽  
Geometric Imperfection ◽  
Manufacture Process ◽  
Buckling Behavior ◽  
Load Carrying ◽  
Thin Walled ◽  
Tolerance Control

The buckling behavior of thin-walled steel structures under load is still imperfectly understood, in spite of much research over the past 50 years. In this paper, the buckling behaviors of H-section columns under compression have been simulated with ANSYS. In the analysis, contact pairs between column ends and end blocks have been introduced into the model, and the load carrying capacity of the columns with four kinds of end constraint conditions and various typical initial geometric imperfections has been calculated and discussed. The results indicate that the load carrying capacity is most sensitive to the flexural imperfection, and the constraint condition cannot change the imperfection sensitivity of a column under compression, but improving restrain condition can heighten the load carrying capacity. They are helpful to the use and the tolerance control in the manufacture process of thin-walled H-section steel structures.

Experimental Investigation on Steel-Plate-Masonry Composite Column Compressive Behavior

2011 ◽  
Vol 255-260 ◽  
pp. 591-595 ◽  
Author(s):  
Deng Hu Jing ◽  
Shuang Yin Cao ◽  
Hai Tao Zhou
Keyword(s):  
Carrying Capacity ◽  
Failure Modes ◽  
Steel Plate ◽  
Local Buckling ◽  
Epoxy Adhesive ◽  
Critical Cross Section ◽  
Load Carrying Capacity ◽  
Large Space ◽  
Composite Column ◽  
Load Carrying

The steel-plate-masonry composite structure is an innovative type of structural scheme popular in masonry structures with load-bearing walls removed for a large space. A total of 4 column specimens under static loading were tested to mainly study the failure modes, load-carrying capacity, and strain distribution in the critical cross-section. Results show that the composite columns started an initial failure from local buckling of the steel plate located between binding bolts; the main factors influencing load-carrying capacity included thickness of the steel plate, type of injected material, and initial column eccentricity; the working performance of the composite column with epoxy adhesive was better than that with cement grout; and re-distribution of compressive stress existed in the steel plates of the column. Also, the ratio of service load-carrying capacity to ultimate capacity of the steel-plate-masonry composite column is about 70%.

Analysis of Load-Carrying Capacity of Thin-Walled Closed Beams with Different Slenderness

2014 ◽  
Vol 969 ◽  
pp. 39-44
Author(s):  
Jan Valeš
Keyword(s):  
Cross Section ◽  
Carrying Capacity ◽  
Random Fields ◽  
Capacity Analysis ◽  
Geometrically Nonlinear ◽  
Load Carrying Capacity ◽  
Design Load ◽  
Steel Members ◽  
Load Carrying ◽  
Thin Walled

The presented paper deals with the load-carrying capacity analysis of compress steel members having the square closed (box) cross-section with non-dimensional slenderness 0.6, 0.8, 1.0 a 1.2. The axis of these beams is randomly three-dimensionally curved. Initial curvatures are modelled by random fields applying the LHS method. Load-carrying capacities are then calculated by the geometrically nonlinear solution using the ANSYS program. The results are presented both in form of histograms and of the table. The analysis of load-carrying capacity of beams with individual nonlinear slenderness is carried out, and the values are compared with the values of design load-carrying capacity according to the standard.

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