Numerical Analysis of Branch Mechanical Response to Loading

Vojáčková, Barbora; Tippner, Jan; Horáček, Petr; Praus, Luděk; Sebera, Václav; Brabec, Martin

doi:10.48044/jauf.2019.011

Cited by 3 publications

(5 citation statements)

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“…Plants 2021, 10, x FOR PEER REVIEW 3 of 14 trees [29]. These numerical strain and stress analyses of tree stem and branches under applied load [13,30] should be confirmed by experimental tests. The submitted article presents the structural analysis of a single tree, where a complex process was used.…”

Section: Resultsmentioning

confidence: 99%

“…The authors of [ 13 ] provided a comparison between numerical analysis and force applied on the four branches from four trees Tilia cordata L. Branches were chosen with different geometrical parameters to verify FE simulations. They differ in diameter, shape of cross section, tapering, and angle of attachment.…”

Section: Discussionmentioning

confidence: 99%

“…At present, an optical technique wherein small dots are sprayed on the tree surface is often used, especially for numerical analysis. This optical strain measurement method shows the strain distribution of trunks and branches under load [13,14].…”

Section: Introductionmentioning

confidence: 99%

“…A review indicates that material properties play only a limited role in tree dynamics and in the form and morphology of the tree and branches, which can influence the dynamics of trees [29]. These numerical strain and stress analyses of tree stem and branches under applied load [13,30] should be confirmed by experimental tests.…”

Section: Introductionmentioning

confidence: 99%

“…Presumption of failure is determined from the bending capacity of the tree, based on geometry and material properties, as well as the anticipated loads and weather [ 5 ]. Tree failure can be divided into two main damages: breakage and uprooting [ 17 ], where the former can be caused by a stem breakage or branch failure [ 13 ]. Resistance assessment against breakage is common at present, but it has reference to limited equipment and unknown input attributes [ 17 ].…”

Section: Introductionmentioning

confidence: 99%

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Analysis of the Static Behavior of a Single Tree on a Finite Element Model

Moravčík

Vincúr

Rózová

2021

Plants

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This work deals with the innovated complex process of tree risk assessment, from precise geometrical tree shape acquisition to building and analyzing a finite element model under specified load. The acquisition of the 3D geometry of the tree was performed by means of terrestrial laser scanning. Obtained point cloud was optimized and additionally converted to a 3D CAD model, representing the bearing skeleton compound of trunk and main branches. For structural analysis purposes, a finite element model (FEM) was built in the form of beam structure fixed to the ground. Particular beams were defined by geometry, material properties of wood, and cross sections. An acoustic tomography was applied for determination of the precise cross section on investigated locations of an analysis model. Finite element analysis performed on the computational model shows the bearing capacity and deformations of the whole tree structure caused by combinations of load cases like self-weight and static equivalent of wind load. The results of the structural analysis called attention to potentially dangerous places within the tree structure with extreme node displacements or tensile stresses on beams. Thus, we observed a maximal horizontal displacement of 280.4 mm in node N34 and dangerous tensile stress in node N26, where it reaches +23.6 MPa. After filtering some beams with an abnormal cross section geometry, the finite element analysis of the whole tree structure showed the highest tensile stress of +8.8 MPa and highest compressive stress of −8.9 MPa. The suggested method can be applied generally for the prediction of potentially risky tree suspected of breakage and especially for monumental trees, where the presented method can be mostly applicable.

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Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Analysis of the Static Behavior of a Single Tree on a Finite Element Model

Moravčík

Vincúr

Rózová

2021

Plants

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Comparing structural models of linear elastic responses to bending in inosculated joints

Middleton

Erdal

Detter

et al. 2023

Trees

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Key message Mechanical models of inosculations benefit from moderate geometric detail and characterisation of the structurally optimised area of interwoven tension-resistant fibres between the branches. Abstract Living architecture is formed by shaping and merging trees, often in combination with non-living technical elements. These structures often employ the mechanical and physiological adaptations of living trees to support structural loads. Designed and vernacular buildings utilise inosculations to redistribute forces, redirect growth, and provide redundancy. Mechanical models of inosculations in living architecture must be built according to the adaptations available to the tree. Here, mass allocation and fibre orientation are examined. Under typical gravity loads, a zone at the top of the inosculation is subject to tension. This is of particular interest because a trade-off in fibre orientation between mechanical and physiological optimisation is necessary. In tree forks, this results in specifically adapted interwoven fibres. In this study, Finite Element Analysis (FEA) is used to develop different mechanical models to fit bending experiments of four Salix alba inosculations, comparing the models’ accuracy in replicating rotations in the joint. Nine models were developed. Three levels of detail of mass allocation are considered for global isotropic (3 models) and orthotropic (3 models) mechanical properties as well as a model including the interwoven tension zone, a model of local branch and trunk orthotropy, and a model combining these two localised features. Results show significant accuracy gains come from moderate geometric accuracy and consideration of the tension-zone optimisation. The construction of the tension zone in FEA is simple and applicable to natural and artificially induced inosculations.

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Elasto-plastic material model of oak at two moisture content levels

et al. 2022

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The mechanical properties of wood show a very high dependence on the moisture content (MC). A consideration of MC in numerical simulations increases the applicability of such prediction with respect to application and moisture states of the wood material. The goal of this work is to develop an accurate orthotropic elasto-plastic model for oak wood (Quercus robur L.) at two different MC levels applicable for finite element analysis (FEA). To achieve this goal, the following steps were carried out: (a) in-house standard specimens tests in compression, tension, and shear and in all three orthogonal directions, followed by three-point bending, where all specimens were conditioned to a 12 and 25.6% MC, prior to the mechanical test; (b) integration of all obtained material characteristics into the consistent numerical material models; (c) validation of the developed material models by comparing the numerically predicted values with the experimental ones; and (d) iterative calibration of the material models by adjusting the individual material characteristics to minimize error using a reference. Material models were successfully developed with the following mean relative errors: 5.2% for 12% MC and 5.8% for 25.6% MC, respectively. Both numerical material models consistently predicted the oak elasto-plastic response that can be easily integrated into any FEA.

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Numerical Analysis of Branch Mechanical Response to Loading

Cited by 3 publications

References 0 publications

Analysis of the Static Behavior of a Single Tree on a Finite Element Model

Analysis of the Static Behavior of a Single Tree on a Finite Element Model

Comparing structural models of linear elastic responses to bending in inosculated joints

Elasto-plastic material model of oak at two moisture content levels

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