scholarly journals Experimental Field Tests and Finite Element Analyses for Rock Cracking Using the Expansion of Vermiculite Materials

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Chi-hyung Ahn ◽  
Jong Wan Hu
Keyword(s):  
Finite Element ◽  
Field Tests ◽  
Experimental Tests ◽  
Heating Time ◽  
Test Results ◽  
Experimental Field ◽  
Expansion Pressure ◽  
Circular Holes ◽  
Granite Rocks ◽  
Good Agreement

In the previous research, laboratory tests were performed in order to measure the expansion of vermiculite upon heating and to convert it into expansion pressure. Based on these test results, this study mainly focuses on experimental field tests conducted to verify that expansion pressure obtained by heating vermiculite materials is enough to break massive and hard granite rock with an intention to excavate the tunnel. Hexahedral granite specimens with a circular hole perforated in the center were constructed for the experimental tests. The circular holes were filled with vermiculite plus thermal conduction and then heated using the cartridge heater. As a result, all of hexahedral granite specimens had cracks in the surface after 700-second thermal heating and were finally spilt into two pieces completely. The specimen of larger size only requires more heating time and expansion pressure. The material properties of granite rocks, which were obtained from the experimental tests, were utilized to produce finite element models used for numerical analyses. The analysis results show good agreement with the experimental results in terms of initial cracking, propagation direction, and expansion pressure.

scholarly journals Static and Fatigue Failures of Adhesively Bonded Laminate Joints in Moist Environments

2011 ◽  
Vol 20 (8) ◽  
pp. 1217-1242 ◽  
Author(s):  
K. B. Katnam ◽  
A. D. Crocombe ◽  
H. Sugiman ◽  
H. Khoramishad ◽  
I. A. Ashcroft
Keyword(s):  
Cohesive Zone ◽  
Experimental Tests ◽  
Static Fatigue ◽  
Test Results ◽  
Adhesively Bonded ◽  
Aerospace Applications ◽  
Numerical Predictions ◽  
Fatigue Failures ◽  
Good Agreement

Advanced structural adhesives are now an important joining technique in automobile and aerospace applications. The perceived uncertainty in the long-term structural performance of bonded members when subjected to static/fatigue loads in aggressive environments is probably restricting an even more widespread use of this joining technology. In this article, the effect of moisture on the static and fatigue resistances of adhesively bonded laminate joints was investigated. Experimental tests were performed on both aged and unaged adhesively bonded laminate joints for static and fatigue responses. Further, using a cohesive zone approach for the adhesive bondlines, a combined diffusion–stress analysis was developed to predict the progressive damage observed in the joints tested experimentally. The numerical predictions were found to be in good agreement with the experimental test results.

Experimental Research and Finite Element Analysis of BFRP Flexural Strengthening Efficiencies of Pre-Damaged Concrete Beams

2013 ◽  
Vol 834-836 ◽  
pp. 720-725 ◽  
Author(s):  
Hai Liang Wang ◽  
Wei Chang ◽  
Xin Lei Yang
Keyword(s):  
Numerical Simulation ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Element Analysis ◽  
Flexural Strengthening ◽  
Flexural Resistance ◽  
Good Agreement

Six reinforced concrete beams, including 4 beams strengthened with BFRP sheets at different layer of BFRP sheets and 2 control beams, are tested to investigate the effect of layer of BFRP sheets on the ultimate flexural resistance and load-deflection response of the pre-damaged concrete beams strengthened with BFRP sheets. Results show that the flexural resistance of pre-damaged concrete beams increases along with the BFRP sheets layer increasing,but the flexural resistance enhances the degree not to assume the linear relations to the enforcement layer.Numerical simulation of the pre-damaged concrete beams strengthened with BFRP sheets is conducted by ANSYS, and the results of numerical simulation are compared with those of the test results. It turns out that the results of numerical simulation are in good agreement with the test results.

Design of a 33-Knot Aluminum Catamaran Ferry

2000 ◽  
Vol 37 (02) ◽  
pp. 88-99
Author(s):  
R. G. Latorre ◽  
P. D. Herrington
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Speed ◽  
Frame Structure ◽  
Test Results ◽  
Finite Element Analyses ◽  
The Finite Element Method ◽  
Floating Frame ◽  
Good Agreement ◽  
Panel Design

This paper presents the results of an investigation on the suitability of using hull panels with alternating fixed and floating frames for a 30–40 knot aluminum catamaran ferry. A prototype 4.6 m × 1.8 m bottom hull panel with alternating frames is analyzed numerically and physically tested. The corresponding finite-element analyses and test results are in good agreement. The results show that the floating frame hull panel design is a feasible structure for an aluminum catamaran. The floating frame structure was then used for a 33-knot, 250-passenger aluminum catamaran ferry designed to meet the ABS High Speed Craft rules. A midship section of the catamaran hull was analyzed using the finite-element method. Catamaran weight estimates, heave and pitch motions, and powering estimates are also provided. The results show that the alternating floating frame structure was within the ABS rules stress allowables.

Novel U-bending designed setups for investigating the spring-back/spring-go of two-layer aluminum/copper sheets through experimental tests and finite element simulations

2020 ◽  
Vol 234 (8) ◽  
pp. 1142-1153 ◽  
Author(s):  
Ehsan Etemadi ◽  
Abbas Naseri ◽  
Mohsen Valinezhad
Keyword(s):  
Finite Element ◽  
Experimental Tests ◽  
Finite Element Simulations ◽  
Curvature Radius ◽  
Stacking Sequence ◽  
Spring Back ◽  
Effective Parameters ◽  
Bending Process ◽  
Copper Aluminum ◽  
Good Agreement

This paper presents novel U-bending setups in order to investigate the effects of the curvatures created on the punch, die, or both on the spring-back/spring-go of the two-layer aluminum/copper sheets. Comparison of the new U-bending setups with the regular ones showed that the curvatures had important roles in reducing the spring-back/spring-go in the U-bending process. The results further indicated the good agreement between spring-back/spring-go and finite element simulations. Moreover, through finite element simulations, the effects of three effective parameters on reducing the spring-back/spring-go, including the curvature radius ( r) of the punch, the distance between curvature center and the fillet center ( d) in the punch, and the curvature radius at the end of the die ( R) were investigated. In achieving the desired state (90°), the results showed that the distance of curvature center from the fillet center ( d) was a more important parameter compared with the curvature radius at the end of the punch ( r) and the curvature radius at the end of the die ( R). This paper also focuses on the thicknesses of copper and aluminum as well as the stacking sequence of layers. Concerning the thicknesses of the implemented copper and aluminum change, the minimum angle of the spring-back/spring-go relative to the desired state was 75% Al/25% Cu thickness. Furthermore, the spring-back of aluminum/copper was lower than the copper/aluminum layer sheet. The effects of both thickness changing and stacking sequence of aluminum/copper layers on the spring-back/spring-go amounts of different sheets were due to the relocation of the neutral axis.

Finite Element Analysis of Hybrid Fiber Reinforced HPC Deep Beams under Shear Load

2013 ◽  
Vol 419 ◽  
pp. 889-894
Author(s):  
Sheng Bing Liu ◽  
Li Hua Xu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Polypropylene Fiber ◽  
Shear Capacity ◽  
Test Results ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Deep Beams ◽  
Element Analysis ◽  
Good Agreement

18 different groups of hybrid fiber (steel fiber and polypropylene fiber) reinforced HPC deep beams and 2 groups of HPC deep beams without fiber were made. The shear tests under the static load and the numerical simulation by ABAQUS were conducted. Good agreement are found between test results and simulation results.The results of finite element analysis indicate that with the increment of reinforcement ratio, the shear capacity of hybrid fiber reinforced HPC deep beams increases, but quite limited. The variation of shear capacity of hybrid fiber reinforced HPC deep beams is not obvious as the shear-span ratio changes (when ) . The increment of span-depth ratio can improve the shear capacity of hybrid fiber reinforced HPC deep beams, but only with small amplitude. All these regularities are similar to those of ordinary reinforced concrete deep beams.

Nonlinear Contact Analysis of Different API Line Pipe Coupling Modifications

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Jeroen Van Wittenberghe ◽  
Patrick De Baets ◽  
Wim De Waele
Keyword(s):  
Finite Element ◽  
Critical Evaluation ◽  
Element Model ◽  
Test Results ◽  
Line Pipe ◽  
Bending Fatigue ◽  
Four Point Bending ◽  
Pipe Coupling ◽  
The Finite Element Model ◽  
Good Agreement

Threaded pipe couplings are used to join pipelines when they have to be uncoupled frequently or as an easy to assemble alternative to welding. A large variety of patented coupling modifications are available, but little is known about their influence on the connection’s behavior. In this study, the finite element model of an API line pipe threaded pipe connection is presented and its nonlinearities in material properties and contact behavior are discussed. Test results obtained from a four-point bending fatigue experiment are in good agreement with the results of the numerical simulations. A series of modifications of the standard connection are simulated to gain a better understanding in the influence of geometrical and material parameters on the connection’s performance. It was found that not all existing coupling modifications are improving the connection’s performance. It can be concluded that critical evaluation of the performance of existing coupling modifications is necessary and finite element analyses are proven to be a useful tool for this.

Finite Element Simulations and Experimental Investigations of Simple 2-D Geometries in Slamming

2008 ◽  
Author(s):  
Adrian Constantinescu ◽  
Alain Neme ◽  
Nicolas Jacques ◽  
Philippe Rigo
Keyword(s):  
Finite Element ◽  
Water Surface ◽  
Free Water ◽  
Experimental Tests ◽  
Experimental Investigations ◽  
Convergence Criterion ◽  
Numerical Work ◽  
Fluid Structure ◽  
The Impact ◽  
Good Agreement

This paper presents a numerical and experimental study of fluid structure interaction during the impact of a solid body on a water surface. The main request is the modeling of the slamming forces acting on the ship structure in severe sea conditions. The numerical work uses the finite element modeling of a structure impact with free water surface. The first analysis use the commercial finite element code ABAQUS/Standard and combines the assumption of small displacements for the ideal fluid and the solid with an asymptotic formulation for accurate pressure evaluation on the boundary of the wet surface. For deformable strickers, two methods are developed. The first method employs a weak fluid-structure coupling. The second method, more accurate, uses an implicit fluid-structure coupling using a convergence criterion. The second analysis is represented by the simulations of slamming with ABAQUS/Explicit. The simulation uses a viscous, compressible fluid and a soft-exponential law to manage the contact between fluid and solid. The results in term of pressure and total effort applied to the rigid structure are in good agreement with first numerical results and especially with the FLUENT CFD. In order to validate the numerical methods, slamming experimental tests were carried out with a new hydraulic shock press at the ENSIETA laboratory.

The Analysis and Tests of Composite Leaf Spring for Trailer Truck

2013 ◽  
Vol 744 ◽  
pp. 383-387
Author(s):  
Jia Shi Wang ◽  
Zai Ke Li ◽  
Qi Bin Jiang ◽  
Wen Li Lv
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Weight Reduction ◽  
Load Capacity ◽  
Experimental Tests ◽  
Maximum Load ◽  
Leaf Spring ◽  
Environment Protection ◽  
Molding Process ◽  
Good Agreement

The composite leaf spring for trailer truck is developed with weight reduction 60% relative to steel spring, which can be benefit to environment protection and energy saving. In this work, the composite leaf spring is designed and analyzed by finite element method. Then the experimental tests are conducted on the composite leaf spring fabricated by the hot molding process. The spring rate and the maximum load capacity are measured, which have a good agreement with the design results.

scholarly journals A comprehensive study on the buckling behaviour of woven composite plates with major aerospace cutouts under uniaxial loading

2019 ◽  
Vol 13 (2) ◽  
pp. 4756-4776 ◽  
Author(s):  
S. B. Rayhan
Keyword(s):  
Finite Element ◽  
Fibre Orientation ◽  
Plate Thickness ◽  
Orientation Angle ◽  
Composite Plates ◽  
Experimental Tests ◽  
Buckling Load ◽  
Critical Buckling Load ◽  
Good Agreement ◽  
Comprehensive Study

Current research paper presents a comprehensive study based on Finite Element Method (FEM) to understand the effect of cutout shape and area on the buckling behaviour of E-glass composite plates. Considered plate has a dimension of 150 mm × 75mm × 3mm where loading edges are simple supported (shorter side) and other two edges are free. Major aerospace cutout shapes i.e. circular, square, elliptical (horizontal and vertical) and diamond are studied to understand their effect on plates’ critical buckling load. FE code Ansys is adopted to investigate the case studies. A limited number of experimental tests are also carried out in order to validate the FE code results. Overall, a good agreement between experimental and FE code results are found. From finite element analyses, it is found that for any cutout shape, as the cutout area increases, buckling load decreases significantly. Moreover, increasing the plate thickness by 0.5 mm can raise the buckling load up to 50%. More importantly, fibre orientation angle has most significant effect on the critical buckling load of plates where fibre orientation aligned with loading direction can increase the plates’ critical buckling load from 2.6 to 2.8 times than aligned with 900.

scholarly journals Advanced Modeling and Simulation of Rockfall Attenuator Barriers Via Partitioned DEM-FEM Coupling

2021 ◽  
Vol 7 ◽  
Author(s):  
Klaus Bernd Sautter ◽  
Helene Hofmann ◽  
Corinna Wendeler ◽  
Peter Wilson ◽  
Philipp Bucher ◽  
...  
Keyword(s):  
Modeling And Simulation ◽  
Experimental Testing ◽  
Experimental Tests ◽  
Simulation Method ◽  
Design Decision ◽  
Test Results ◽  
The Finite Element Method ◽  
Shape Sphere ◽  
Good Agreement ◽  
Element Method

Attenuator barriers, in contrast to conventional safety nets, tend to smoothly guide impacting rocks instead of absorbing large amounts of strain energy arresting them. It has been shown that the rock’s rotation plays an important role in the bearing capacity of these systems. Although experimental tests have to be conducted to gain a detailed insight into the behavior of both the structures and the rock itself, these tests are usually costly, time-consuming, and offer limited generalizability to other structure/environment combinations. Thus, in order to support the engineer’s design decision, reinforce test results and confidently predict barrier performance beyond experimental configurations this work describes an appropriate numerical modeling and simulation method of this coupled problem. For this purpose, the Discrete Element Method (DEM) and the Finite Element Method (FEM) are coupled in an open-source multi-physics code. In order to flexibly model rocks of any shape, sphere clusters are used which employ simple and efficient contact algorithms despite arbitrarily complicated shapes. A general summary of the FEM formulation is presented as well as detailed derivations of finite elements particularly pertinent to rockfall simulations. The presented modeling and coupling method is validated against experimental testing conducted by the company Geobrugg. Good agreement is achieved between the simulated and experimental results, demonstrating the successful practical application of the proposed method.

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