Analysis of Bending Loads on Bamboo-Balsa and Bamboo-Polypropylene Honeycomb Composite Sandwiches

2015 ◽  
Vol 1125 ◽  
pp. 94-99 ◽  
Author(s):  
Aldyandra Hami Seno ◽  
Eko Koswara ◽  
Hendri Syamsudin ◽  
Djarot Widagdo
Keyword(s):  
Failure Modes ◽  
Shear Failure ◽  
Numerical Models ◽  
Future Research ◽  
Test Results ◽  
Bending Tests ◽  
Bending Loads ◽  
Bending Behavior ◽  
Honeycomb Cores ◽  
Load Deflection Curve

This research was done to evaluate the bending behavior (load-deflection curve and failuremode) of sandwich structures using Tali Bamboo strips as sandwich skin material. Bending tests wereconducted on sandwich specimens with end grain balsa (3-point bending) and polypropylene (PP)honeycomb cores (4-point bending) to evaluate their bending behavior. From the test results,analytical and numerical models were developed to simulate the observed bending behavior. Themodels are able to simulate the pre-failure bending behavior and failure modes (core shear failure) ofthe specimens. It is also shown that for thin (length/thickness > 20) sandwiches the models are moreaccurate since shear effects are less prominent. With the obtained models a predictive comparison isdone between the PP and balsa cored specimens since the testing configuration for each type wasdifferent. The analysis results show that balsa cored specimens are able to withstand higher transversebending loads due to the higher shear strength of the balsa core. These prediction results are to beproven by specimen testing which is the subject of future research.

Experimental Study on Interlaminar Shear Properties of T300/BMI Composite Laminates

2013 ◽  
Vol 718-720 ◽  
pp. 157-161
Author(s):  
Zong Hong Xie ◽  
Hai Han Liu ◽  
Jian Zhao ◽  
Jun Feng Sun ◽  
Fei Peng ◽  
...  
Keyword(s):  
Composite Laminates ◽  
Shear Test ◽  
Failure Modes ◽  
Shear Failure ◽  
Test Method ◽  
Test Results ◽  
Shear Properties ◽  
Test Fixture ◽  
Iosipescu Shear Test ◽  
Interlaminar Shear

A modified test fixture to measure the shear properties of composite laminates was designed and manufactured based upon Iosipescu shear test method. Tests on interlaminar shear propertis of T300/BMI composite laminates were conducted according to ASTM D 5379 test standard. Interlaminar shear stress/strain curves and shear failure modes were obtained. The test results showed that the modified shear test fixture and test method were effective in measuring the shear properties of composite laminates.

Overlapped K Joints in Circular Hollow Sections Under Axial Loading (An Investigation of the Factors Affecting the Static Strength Using Numerical Modeling)

1996 ◽  
Vol 118 (1) ◽  
pp. 53-61 ◽  
Author(s):  
E. M. Dexter ◽  
M. M. K. Lee ◽  
M. G. Kirkwood
Keyword(s):  
Failure Modes ◽  
Load Transfer ◽  
Numerical Models ◽  
Axial Loading ◽  
Static Strength ◽  
Test Results ◽  
Factors Affecting ◽  
Current Design ◽  
The Relationship ◽  
Design Guidance

Overlapped joints are generally regarded as having higher strengths than otherwise identical, simple nonoverlapping joints because of the more efficient load transfer between braces. However, not only that relatively little research has been carried out on such joints, the few test data from which current design guidance was derived has also been recently rejected. This paper reports the first phase of a parametric finite element study into the strength of overlapping K joints under axial loading. The numerical models were validated and calibrated against existing gap and overlapped K joint test results, and various factors which affect the relationship between the strength and the overlap amount, such as boundary restraints, hidden welds, loading hierarchy, and failure modes, were investigated. The results of the work presented lay the foundation for a future parametric study.

scholarly journals In-Plane Behaviour of Masonry Walls: Numerical Analysis and Design Formulations

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5780
Author(s):  
Thomas Celano ◽  
Luca Umberto Argiento ◽  
Francesca Ceroni ◽  
Claudia Casapulla
Keyword(s):  
Failure Modes ◽  
Shear Failure ◽  
Numerical Models ◽  
Experimental Tests ◽  
Element Model ◽  
Masonry Walls ◽  
Analysis And Design ◽  
Non Linear ◽  
Failure Loads ◽  
Modelling Approaches

This paper presents the results of several numerical analyses aimed at investigating the in-plane resistance of masonry walls by means of two modelling approaches: a finite element model (FEM) and a discrete macro-element model (DMEM). Non-linear analyses are developed, in both cases, by changing the mechanical properties of masonry (compressive and tensile strengths, fracture energy in compression and tension, shear strength) and the value of the vertical compression stress applied on the walls. The reliability of both numerical models is firstly checked by means of comparisons with experimental tests available in the literature. The analyses show that the numerical results provided by the two modelling approaches are in good agreement, in terms of both failure loads and modes, while some differences are observed in their load-displacement curves, especially in the non-linear field. Finally, the numerical in-plane resistances are compared with the theoretical formulations provided by the Italian building code for both flexural and shear failure modes and an amendment for the shape factor ‘b’ introduced in the code formulation for squat walls is proposed.

scholarly journals Experimental Study on the Mechanical Behavior of Yunnan Limestone in Natural and Saturated States

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Xutao Zhang ◽  
Mingyang Ren ◽  
Zhaobo Meng ◽  
Baoliang Zhang ◽  
Jinglong Li
Keyword(s):  
Elastic Modulus ◽  
Mechanical Behavior ◽  
Water Content ◽  
Failure Modes ◽  
Shear Failure ◽  
Mechanical Response ◽  
Deformation Modulus ◽  
Confining Pressure ◽  
Hyperbolic Function ◽  
Test Results

Rock material is a kind of mineral assemblage with complex structural heterogeneity, whose mechanical behavior is strongly affected by water or moisture content. In this work, we carried out a series of laboratory tests to investigate the mechanical response (e.g., deformation, strength, and failure characteristics) of Yunnan limestone in natural and saturated states. Our test results show that (1) after saturation, the stiffness and strength of Yunnan limestone degenerate considerably. Compared with the natural condition, the elastic modulus, deformation modulus, and tensile modulus decrease by about 30% on average, and uniaxial compressive strength and tensile strength also decrease by about 15% and 20%, respectively. While Poisson’s ratio is less affected by water content, it can be regarded as a constant; (2) the elastic modulus and deformation modulus of Yunnan limestone are significantly affected by confining pressure, and the relationship between them and confining pressure satisfies the law of hyperbolic function; (3) the peak strength envelope of Yunnan limestone has significant nonlinear characteristics, which can be well described by generalized Hoek-Brown strength criterion. However, the generalized Hoek-Brown criterion does not apply to the residual strength, which shows a linearly increasing trend with the increasing confining pressure; (4) the failure modes of Yunnan limestone are significantly dependent on confining pressure but insensitive to water content. With the increasing confining pressure, the failure modes of Yunnan limestone transform from splitting failure, tension-shear mixed failure, single inclined plane shear failure to Y-shaped or X-shaped conjugated shear failure. The test results can provide important experimental data for the establishment of the constitutive model of Yunnan limestone, which will contribute to obtain more reliable results for stability assessment of Xianglu Mountain Tunnel.

scholarly journals BEHAVIOR OF LIGHTWEIGHT SELF-COMPACTED CONCRETE USING ATTAPULGITE STONE AS AGGREGATE AND SUBJECTED TO AXIAL LOAD

2021 ◽  
Vol 25 (Special) ◽  
pp. 4-78-4-87
Author(s):  
Heba S. Qassim ◽  
◽  
Wissam K. AL-Saraj ◽  
Keyword(s):  
Silica Fume ◽  
Axial Load ◽  
Concrete Beam ◽  
Shear Failure ◽  
Experimental Studies ◽  
Shear Capacity ◽  
Shear Stresses ◽  
Test Results ◽  
Effective Depth ◽  
Bending Loads

This paper presents experimental studies of rectangular concrete beam behaviors under axial load and bending loads and investigating the possibility of producing Lightweight Self-Compacting Concrete (LWSCC) by using the Attapulgite stone with a bulk density of about 776 kg/m3. The experimental work included (5) specimens which included using the silica fume by 10% and 15% as an addition to the mixture M2 and M3 . The shear span to effective depth (a/d) of beams was (2.5, 2.75, and 3.00). The test results showed an improvement in the mechanical properties of specimens containing silica fume by 15%, which was tested at 28 days. The first crack and the ultimate load were decreasing with increasing (a/d) ratios. Experimental results indicate a significant improvement in the properties of concrete and its resistance to shear stresses, as the axial load improves the shear capacity and reduces the shear failure in the (LWSCC).

scholarly journals Effects of layer number and finger direction on bending behavior of glulam beams

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 4217-4233
Author(s):  
Ümmü Karagöz İşleyen ◽  
İrfan Peker
Keyword(s):  
Experimental Design ◽  
Orthogonal Experimental Design ◽  
Test Results ◽  
Bending Tests ◽  
Glulam Beam ◽  
Finger Joints ◽  
Four Point Bending ◽  
Number Of Layers ◽  
Bending Behavior ◽  
Lamination Thickness

Effects of the number of layers and the number and typology of finger joints were studied relative to the bending behavior of glulam beam made of Scots pine (Pinus sylvestris) laminates. The investigated parameters of glulam beams with constant overall dimensions (width × depth × length) of 90 mm × 90 mm × 1710 mm were lamination thickness (18 mm or 30 mm), the distance of the finger joints (200, 400, and 600 mm), and finger direction (horizontal and vertical). A total of 14 experimental samples were produced (12 different finger joint beams and two reference beams without finger joints) and tested under four-point bending tests. Taguchi orthogonal experimental design was used to evaluate and optimize test results using the S/N ratio. The effects of main and interactions between producing parameters on strength of glulam beam were determined by variance analysis. According to the results of the analysis, it was determined that the number of layers and the direction of the finger had a significant effect on the flexural strength of the beams, but the finger distance was not significant. Moreover, the highest strength values were obtained in 5-layer finger-jointed beams with vertical finger direction.

Composite Slabs with Prepressed Embossments – Longitudinal Shear Resistance

2015 ◽  
Vol 769 ◽  
pp. 289-293
Author(s):  
Josef Holomek ◽  
Miroslav Bajer ◽  
Jan Barnat ◽  
Martin Vild
Keyword(s):  
Failure Mode ◽  
Shear Failure ◽  
Numerical Models ◽  
Shear Resistance ◽  
Longitudinal Shear ◽  
Small Scale ◽  
Bending Tests ◽  
Composite Action ◽  
Composite Slabs ◽  
Shear Characteristics

Composite slabs with prepressed embossments present an effective solution for horizontal structures. Prepressed embossments ensure composite action after hardening of concrete. Longitudinal shear failure mode typically governs if the shear resistance of embossments is not sufficient for full composite action. Mutual separation of thin-walled sheeting from concrete and its deformation inside the rib is characteristic for this failure mode. Design methods for composite slabs use full scale bending tests in several series to determine their bearing capacity. A less expensive alternative is to use small-scale shear tests to determine shear characteristics of the sheeting. This paper presents detailed numerical models of slab in shear and models of slab in bending with and without embossments. These models are compared with previously performed experiments. Key WordsComposite slab; steel sheeting; concrete; prepressed embossment; longitudinal shear; experiment; numerical model

scholarly journals Parametric Study on Mixed Torsional Behavior of U-Shaped Thin-Walled RC Girders

2018 ◽  
Vol 2018 ◽  
pp. 1-18
Author(s):  
Jianchao Xu ◽  
Bo Diao ◽  
Quanquan Guo ◽  
Yinghua Ye ◽  
Y. L. Mo ◽  
...  
Keyword(s):  
Failure Modes ◽  
Shear Failure ◽  
Test Results ◽  
Height Ratio ◽  
Calculating Method ◽  
Concrete Girders ◽  
Flexural Failure ◽  
Parametric Studies ◽  
Thin Walled ◽  
Shear Failures

Nowadays, U-shaped thin-walled concrete girders have been widely applied in the urban construction of rail viaducts in China as well as worldwide. However, the mixed torsional behaviors of these structures are not well understood. In this paper, the mixed torsional behaviors of the U-shaped thin-walled RC girders are theoretically analyzed, and a method predicting failure modes and ultimate torques is proposed. Nonlinear FE models based on ABAQUS to simulate the mixed torsional behaviors are built and calibrated with the test results. Parametric studies considering three crucial parameters (boundary condition, span length-section height ratio, and ratio of longitudinal bars to stirrups) are conducted based on both the above suggested calculating method and the FE modeling. The calculated and the simulated results agree well with each other and with the test results. It is found that the failure modes of the U-shaped thin-walled RC girders under torsion are influenced by all the three parameters. Three kinds of failure modes are observed: flexural failures dominated by warping moment, shear failures caused by warping torque and circulatory torque, and flexural-shear failures in the cases where flexural failure and shear failure appear almost at the same time.

scholarly journals Axial Uplift Behaviour of Belled Piers in Coarse-Grained Saline Soils

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Jian Xu ◽  
Jianwei Ren ◽  
Songhe Wang ◽  
Long Jin ◽  
Jun Yuan
Keyword(s):  
Bearing Capacity ◽  
Transmission Lines ◽  
Failure Modes ◽  
Shear Failure ◽  
Empirical Equation ◽  
Coarse Grained ◽  
Saline Soils ◽  
Test Results ◽  
Linear Change ◽  
Load Displacement

Bearing capacity of belled pier foundation is critical in designing transmission lines in coarse saline soil region. This paper describes model test results on belled pier foundations. Axial uplift behaviours including failure modes, load-displacement curves, and ultimate uplift bearing capacity were discussed. The failure planes in four cases were obtained from pulled out cone-shaped bodies. An empirical equation was developed with a critical parameter of an uplift angle in design. Results indicate the range where the ground uplift shows circular extension at higher loads and the overall shear failure finally occurred. The load-displacement curves are primarily softening, and the uplift bearing capacity for coarse-grained saline soils (CSS) in the crystalline state increases at larger thickness, higher than that in dissolved state. Failure planes all exhibit approximately linear change from bottom to up. The angles of uplift for soils in crystalline and dissolved states can be taken as 34° and 18°, while 32° for the conventional for the sake of safety. Uplift behaviour of belled piers in CSS was modelled incorporating a practical interface model, with both failure planes and plastic range.

scholarly journals Evaluation of punching shear capacity of two-way RC slabs without transverse reinforcement according to different provisions

2021 ◽  
Vol 15 (3) ◽  
pp. 171-184
Author(s):  
Tran Xuan Vinh ◽  
Nguyen Trung Hieu ◽  
Pham Xuan Dat ◽  
Nguyen Manh Hung
Keyword(s):  
Failure Modes ◽  
Shear Failure ◽  
Shear Capacity ◽  
Punching Shear ◽  
Test Results ◽  
Flat Slabs ◽  
Comparison Results ◽  
Eurocode 2 ◽  
Effective Depth ◽  
Rc Slabs

Currently, RC flat slabs are being used commonly because of their advantages. Punching shear failure is one of the governing failure modes of RC flat slabs without column capital and drop panels. In this paper, the provisions for predicting the punching shear capacity of two-way reinforced concrete (RC) flat slabs without shear reinforcement including ACI 318-19, Eurocode 2 and TCVN 5574:2018 provisions are reviewed by mean of considering the influences of the main parameters (effective depth, compressive strength of concrete, loaded area, reinforcement ratio). A total of 169 test results collected from the literature were used to compare with the provisions. The aim of this study was to evaluate the level of applicability of predicting the punching shear capacity of two-way RC flat slabs according to these provisions. The comparison results indicated that the Eurocode 2 provision provides the most accurate prediction of punching shear capacity of two-way RC flat slabs.

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