scholarly journals Experimental and Numerical Investigation into Failure Modes of Tension Angle Members Connected by One Leg

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5141
Author(s):  
Edyta Bernatowska ◽  
Lucjan Ślęczka

This paper presents the results of experimental and numerical tests on angle members connected by one leg with a single row of bolts. This study was designed to determine which failure mode governs the resistance of such joints: net section rupture or block tearing rupture. Experimental tests were insufficient to completely identify the failure modes, and it was necessary to conduct numerical simulations. Finite element analysis of steel element resistance based on rupture required advanced material modelling, taking into account ductile initiation and propagation of fractures. This was realised using the Gurson–Tvergaard–Needleman porous material model, which allows for analysis of the joint across the full scope of its behaviour, from unloaded state to failure. Through experimental testing and numerical simulations, both failure mechanisms (net section and block tearing) were examined, and an approach to identify the failure mode was proposed. The obtained results provided experimental and numerical evidence to validate the strength function used in design standards. Finally, the obtained results of the load capacity were compared with the design procedures given in the Eurocode 3′s current and 2021 proposed editions.

Meccanica ◽  
2020 ◽  
Vol 55 (12) ◽  
pp. 2337-2352 ◽  
Author(s):  
Paweł Baranowski ◽  
Łukasz Mazurkiewicz ◽  
Jerzy Małachowski ◽  
Mateusz Pytlik

AbstractIn this paper, the Johnson-Holmquist II (JH-2) model with parameters for a dolomite rock was used for simulating rock fragmentation. The numerical simulations were followed by experimental tests. Blast holes were drilled in two different samples of the dolomite, and an emulsion high explosive was inserted. The first sample was used to measure acceleration histories, and the cracking pattern was analyzed to perform a detailed study of the blast-induced fracture to validate the proposed method of modelling and to analyze the capability of the JH-2 model for the dolomite. The second sample was used for further validation by scanning the fragments obtained after blasting. The geometries of the fragments were compared with numerical simulations to further validate the proposed method of modelling and the implemented material model. The outcomes are promising, and further study is planned for simulating and optimizing parallel cut-hole blasting.


2014 ◽  
Vol 601 ◽  
pp. 231-234
Author(s):  
Cristian Lucian Ghindea ◽  
Dan Cretu ◽  
Monica Popescu ◽  
Radu Cruciat ◽  
Elena Tulei

As a general trend, in order to reduce material consumption or to reduce the mass of the structures, composite floor slabs solutions are used to achieve large spans floor slabs. This solutions led to floors sensitive to vibrations induced generally by human activities. As a verification of the design concepts of the composite floors, usually, it is recommended a further examination of the floor after completion by experimental tests. Although the experimental values of the dynamic response of the floor are uniquely determined, the processing can take two directions of evaluation. The first direction consist in determining the dynamic characteristics of the floor and their comparison with the design values. Another way that can be followed in the processing of the experimental results is to consider the human perception and comfort to the vibration on floors. The paper aims to present a case study on a composite floor, with steel beams and concrete slab, tested on-site. Both aspects of data processing are analyzed, in terms of the structural element, and in terms of the effect on human perception and comfort. Experimentally obtained values for the dynamic characteristics of the floor are compared with numerical values from finite element analysis, while the second type of characteristic values are compared with various human comfort threshold values found in international standards.


Author(s):  
David Newborn ◽  
Nels Sultan ◽  
Pierre Beynet ◽  
Tim Maddux ◽  
Sungwon Shin ◽  
...  

Large-scale hydraulic model tests and detail numerical model investigations were conducted on recurved wave deflecting structures to aid in the design of wave overtopping mitigation for vertical walls in shallow water. The incident wave and storm surge conditions were characteristic return period events for an offshore island on the North Slope of Alaska. During large storm events, despite depth-limited wave heights, a proposed vertical wall extension was susceptible to wave overtopping, which could potentially cause damage to equipment. Numeric calculations were conducted prior to the experimental tests and were used to establish the relative effectiveness of several recurved parapet concepts. The numerical simulations utilized the COrnell BReaking waves and Structures (COBRAS) fluid modeling program, which is a Volume-of-Fluid (VOF) model based on Reynolds Averaged Navier-Stokes equations [1] [2]. The experimental testing was conducted in the Large Wave Flume (LWF) at Oregon State University, O.H. Hinsdale Wave Research Laboratory. The experimental test directly measured the base shear force, vertical force, and overturning moment applied to the recurved parapets due to wave forcing. Wave impact pressure on the parapet and water particle velocities seaward of the wall were also measured. Results from the experimental testing include probability of exceedance curves for the base shear force, vertical force, and overturning moment for each storm condition. Qualitative comparisons between the experimental tests and the COBRAS simulations show that the numerical model provides realistic flow on and over the parapet.


2012 ◽  
Vol 166-169 ◽  
pp. 1489-1497 ◽  
Author(s):  
Shi Yan ◽  
Lei Liu ◽  
Peng Li ◽  
Zhi Qiang Xin ◽  
Bao Xin Qi

The dynamic response and failure mode of light-weight steel columns under blast loads were studied in this paper by using nonlinear finite element analysis (FEA) software ANSYS/ LS-DYNA, aiming to develop the degree and modes of the excessive plastic deformation during failures of the columns under diverse parameters. The damaged columns with initial blast-induced deformation may evidently influence vertical stability of light-weight steel frame structures. During the numerical simulation, the element of three dimensional solid SOLID164 was used, and the strain rate effect on material strength was included in the material model with Plastic-Kinematic (MAT-03). The main parameters included in the analysis were boundary conditions, scaled distances of explosions, and the vertical compressive load ratios applied on tops of the columns. The results showed that the column with both two fixed ends was the most beneficial to resist blast shock wave, the horizontal displacement at the middle span of the columns were obviously decreasing as increasing of the scaled distances of the explosion, and the axial compression ratio only significantly influenced the column with a sliding end. The failure modes of the developed columns may be summarized as bending failure, direct shear failure, and bending shear combination failure.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Jian Hou ◽  
Li Song

The present study investigated the various failure modes of strengthened steel columns by mortar-filled fiber-reinforced polymer (FRP) tubes to analytically formulate the ultimate capacities of these steel columns. A simple and effective method, wherein a mortar-filled FRP tube was sleeved outside the steel member, was also formulated to enhance the buckling resistance capacity of compressed steel members. In addition, to facilitate the connection of the column to other structural members, the length of the sleeved mortar-filled FRP tubes is less than that of the original steel columns. Theoretical analyses were also performed on the critical sections of such composite columns at their ultimate states to identify their potential failure modes, such as FRP-tube splitting at the ends or on the insides of wrapped areas, local buckling at the steel ends of transition zones, and global buckling of the composite columns. The corresponding ultimate capacity of each failure mode was then analytically formulated to characterize the critical failure mode and ultimate load capacity of the columns. The current theoretical results were compared with those from literature to validate the applicability of the developed ultimate limit design approaches for FRP-mortar-steel composite columns.


2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Lidan Mei ◽  
Nan Guo ◽  
Ling Li ◽  
Hongliang Zuo ◽  
Yan Zhao

AbstractTraditional glulam beam connection mode has a weak ability to transfer bending moment, leading to insufficient joint stiffness and mostly in the form of simply supported beams. To make full use of material strength, a novel prestressed glulam continuous beam was proposed. On this basis, this paper put forward a new method to further improve the mechanical performance of the beams by controlling prestress. According to the estimated ultimate loads of the beams, six different control range values were formulated, and 12 continuous beams were tested for flexural performance. The effects of prestressing control on the failure modes, ultimate load capacity, and load versus deformation relationships of the glulam continuous beams were analyzed. The test results indicated that the flexural performance of the beams with prestressed control was significantly improved compared to the uncontrolled beams, the ultimate load was enhanced by 13.60%–45.11%, and the average steel wire stress at failure was increased from 70% of the designed tensile strength to 94%. Combined with the finite element analysis (FEA), the reasonable control range of the prestressed control continuous beams was18%–30% of the estimated ultimate load. The research in this paper can provide references for the theoretical analysis and engineering application of similar structures.


1987 ◽  
Vol 15 (2) ◽  
pp. 134-158 ◽  
Author(s):  
N-T. Tseng

Abstract Axisymmetric analysis of an inflated tire rotating with constant angular speed can be used to simulate two loading conditions of a tire during its service life: (1) a freely rotating tire on an automobile that is stuck in snow or mud and (2) the top region of a rolling loaded tire, where footprint loading has little influence on the distribution of its stresses and strains. The equations of motion for a freely rotating deformable body with constant angular speed have been derived and implemented into a finite element code developed in-house. The rotation of a thin disk was used to check the validity of the implemented formulation and coding. Excellent agreement between the numerical and the analytical results was obtained. A cast tire, a radial automobile tire, and a radial truck tire, were then analyzed by the new finite element procedure. The tires were inflated and rotated at speeds up to 241 km/h (150 mph). The elastomers in these tires were simulated by incompressible elements for which the nonlinear mechanical properties were described by the Mooney-Rivlin model. Each ply was simulated by its equivalent orthotropic material model. The finite element predictions agreed well with the available experimental measurements. Significant changes in interply shear strain at the belt edge, the bead load, and the crown cord loads of plies were observed in the finite element analysis. These phenomena suggest three possible failure modes in freely rotating tires, i.e. belt edge separation, bead breakage, and belt failure at crown region.


2015 ◽  
Vol 664 ◽  
pp. 285-294 ◽  
Author(s):  
D.S. Paolino ◽  
A. Tridello ◽  
G. Chiandussi ◽  
Massimo Rossetto

In recent years, experimental tests investigating properties of materials in gigacycle regime have suggested modifications to well-known statistical fatigue life models. Classical fatigue life models based on a single failure mode and by the presence of the fatigue limit, have been integrated by models that can take into account the occurrence of two failure modes (duplex S-N curve).Duplex S-N models involve a number of unknown parameters that must be statistically estimated from experimental data. The present paper proposes a simplified and automated procedure for statistical parameter estimation. The procedure is applied to experimental datasets taken from the literature. Parameter estimation is carried out by applying the Maximum Likelihood Principle and by taking into account the possible presence of runout specimens with unequal number of cycles. The application of the procedure permits to estimate different key material parameters (e.g., the characteristic parameters of transition stress and fatigue limit), as well as to statistically predict the failure mode of each tested specimen.


2013 ◽  
Vol 577-578 ◽  
pp. 617-620
Author(s):  
Xiao Qing Xu ◽  
Yu Qing Liu ◽  
Jun He ◽  
Jie Luo

Rubber-sleeved headed stud shear connector is flexible shear connector used in steel-concrete composite structures. In this work, nonlinear finite element model has been developed to simulate the failure process of the shear connector under shear loading. The stress distribution, deformation, crack propagation and failure mode were analyzed. The material nonlinearities of rubber, headed stud, concrete were considered in the material model. The rubber was assumed as a perfect material with no defect, and a modified reduced polynomial form of strain energy including an energy limiter and a new constant was introduced into the user material subroutine VUANISOHYPER-INV of ABAQUS software. Damaged plasticity model was used to model the concrete material. A tri-linear elastic-plastic curve was used in stud material model. Comparing the results obtained from the finite element analysis with those from push-out test, good agreement is highlighted in the capacity, ductility and failure mode of rubber-sleeved headed stud shear connector.


2013 ◽  
Vol 12 (1) ◽  
pp. 131-138
Author(s):  
Renata Kotynia ◽  
Michał Staśkiewicz

The subject of the paper is the analysis of the efficiency of strengthening of RC structures for flexure with use of prestressed CFRP composites. Basic methods of application of the strengthening are described along with the issues connected with the prestressing and anchorage of the CFRP materials. The authors prepared a database of the results of experimental tests based on the published research, which was the basis for the analysis of failure modes of the strengthened members and its efficiency depending on the  characteristics of members. The aim of the paper was to define the influence of steel reinforcement ratio, composite reinforcement ratio and initial CFRP prestressing strain on the efficiency of the applied strengthening in terms of load capacity and serviceability conditions.


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