CLT beam analysis using classical elastic theory of layered beams

The classical elastic theory of layered beams is used for the analysis of cross laminated timber (CLT) beams. A brief introduction of the theory is given and followed by examples. The theory of layered beams offers a widely studied, well established method for the analysis the CLT beams including displacements and stresses of each layer of the beam. It is shown that the theoretical basis of the widely used Shear Analogy is the same as the theoretical basis of the theory of layered beams. The results are compared to test results and to results of the finite element calculations. It is seen that the deflections and strains are in 10 % fractals in mean in the considered cases. The theory of layered beams seems to be suitable method in the analysis of the CLT beams at the elastic phase.

Structural Behavior Of Simple Supported Two Layers Reinforced Concrete (Normal strength concrete & Mortar with 3-Dimension glass fiber), Beams

This paper represents an experimental investigation of the layered concrete beam. It contains studying the possibility of using the mortar intervention with layers of glass fibre at the tension zone in a loaded supported concrete beam. To produce a beam with less weight than the beam with all Normal concrete and detecting the effect of this replacement on beam properties. A rectangular beams section (150*200*1000)mm cast with NSC (normal strength concrete) at compression zone and mortar with layers of 3D glass fibre used as a part of the tension zone. The produced beams are layered beams with a lighter weight than the homogenous RC beam. Three deferent levels of the replaced layers (1/3,1/2, and 2/3 of the beam thickness) were studied, all beams were tested under Two point load till failure. The maximum load capacity result shows an apparent lowering in the load capacity of the beam, but as the lightweight layer increases, this lowering in the load capacity becomes less. for (1/3,1/2 and 2/3) of the beam thickness replace with mortar and 3D textile fibre, the lowering percentage of failure load compare with the homogenous reinforced concrete beam are (33.04%, 27.18%, and 19.73%), and the lowering in weight is (5.45%%, 9.07%, and 12..92%) for the same sequence, respectively. Stiffness, ductility and toughness of all beams are tested. An apparent lowering in the stiffness value of the layered beams is recorded with the reference ones. At the same time, it shows an increase in the toughness and toughness value

Free Vibration Analysis Of Layered Beams With Delamination Damage-An ANSYS®-Based FEM Investigation

Identifying delamination has been a focal point for many researchers. The reason for this interest arises from criticality of delamination in a variety of industries: automotive, aerospace, and construction. Therefore, vibration-based damage identification method is applied to detect, locate and characterize the damage in a mechanical structure. In this method, natural frequency as a diagnostic tool to determine the integrity of a structure has been utilized. The current research presents a FEM-based investigation into free vibrational analysis of defective layered beams with free mode delamination. It is shown that the size, type and location of delamination directly influence system non-dimensional frequencies. Based on an existing 1D model, the investigation is extended to 2D modelling for single-and-double-delamination cases. In each case, Fixed-Fixed and cantilevered beam configurations, both centred and off-centred delamination conditions are studied. Further, a 3D model is also developed for single delamination of a Fixed-Fixed beam. All simulation results show excellent agreement with the data available in the literature. The ANSYS ® FEM-based modelling approach presented here is general and accurately predicts delamination effects on the frequency response of beam structures.

Free Vibration Analysis Of Layered Beams With Delamination Damage-An ANSYS®-Based FEM Investigation

Identifying delamination has been a focal point for many researchers. The reason for this interest arises from criticality of delamination in a variety of industries: automotive, aerospace, and construction. Therefore, vibration-based damage identification method is applied to detect, locate and characterize the damage in a mechanical structure. In this method, natural frequency as a diagnostic tool to determine the integrity of a structure has been utilized. The current research presents a FEM-based investigation into free vibrational analysis of defective layered beams with free mode delamination. It is shown that the size, type and location of delamination directly influence system non-dimensional frequencies. Based on an existing 1D model, the investigation is extended to 2D modelling for single-and-double-delamination cases. In each case, Fixed-Fixed and cantilevered beam configurations, both centred and off-centred delamination conditions are studied. Further, a 3D model is also developed for single delamination of a Fixed-Fixed beam. All simulation results show excellent agreement with the data available in the literature. The ANSYS ® FEM-based modelling approach presented here is general and accurately predicts delamination effects on the frequency response of beam structures.

On the Finite Element Free Vibration Analysis of Delaminated Layered Beams: A New Assembly Technique

The dynamic analysis of flexible delaminated layered beams is revisited. Exploiting Boolean vectors, a novel assembly scheme is developed which can be used to enforce the continuity requirements at the edges of delamination region, leading to a delamination stiffness term. The proposed assembly technique can be used to form various beam configurations with through width delaminations, irrespective of the formulation used to model each beam segment. The proposed assembly system and the Galerkin Finite Element Method (FEM) formulation are subsequently used to investigate the natural frequencies and modes of 2- and 3-layer beam configurations. Using the Euler-Bernoulli bending beam theory and free mode delamination, the governing differential equations are exploited and two beam finite elements are developed. The free bending vibration of three illustrative example problems, characterized by delamination zones of variable length, is investigated. The intact and defective beam natural frequencies and modes obtained from the proposed assembly/FEM beam formulations are presented along with the analytical results and those available in the literature

On the Finite Element Free Vibration Analysis of Delaminated Layered Beams: A New Assembly Technique

The dynamic analysis of flexible delaminated layered beams is revisited. Exploiting Boolean vectors, a novel assembly scheme is developed which can be used to enforce the continuity requirements at the edges of delamination region, leading to a delamination stiffness term. The proposed assembly technique can be used to form various beam configurations with through width delaminations, irrespective of the formulation used to model each beam segment. The proposed assembly system and the Galerkin Finite Element Method (FEM) formulation are subsequently used to investigate the natural frequencies and modes of 2- and 3-layer beam configurations. Using the Euler-Bernoulli bending beam theory and free mode delamination, the governing differential equations are exploited and two beam finite elements are developed. The free bending vibration of three illustrative example problems, characterized by delamination zones of variable length, is investigated. The intact and defective beam natural frequencies and modes obtained from the proposed assembly/FEM beam formulations are presented along with the analytical results and those available in the literature