Gergely Bojtár

57193138553

Publications - 3

The Effect of Ratio of Fiber Bundles in the Textile Composite Layer

Gergely Bojtár

Publication Name: Strojnicky Casopis

Publication Date: 2024-11-01

Volume: 74

Issue: 2

Page Range: 1-10

Description:

The article shows how the orthotropic material properties of the textile composite layer change if the ratio of longitudinal and transversal fiber bundles in the textile is modified in the case of a composite reinforced with plain weave textile. I determine the material properties using model-cell and finite element simulation. The density of the longitudinal fiber bundles is the same in each of the five examined layer models. I change the ratio of the fiber bundles of the textile by varying the distance of the transversal roving's in each model.

Open Access: Yes

DOI: 10.2478/scjme-2024-0019

Numerical determination of orthotropic material properties of textile composite layers and their validation by measurement

Béla M. Csizmadia Gergely Bojtár János Égert

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2017-01-01

Volume: 14

Issue: 2

Page Range: 47-67

Description:

The knowledge of orthotropic material properties of composite layers is very important for mechanical design of machine structures from composite material. This information cannot be found in related professional literature therefore it is necessary to determine by measurement, by basic experiments of mechanics of materials. The paper presents a new 3D finite element layer model-cell based on the meso-structure of a textile composite layer, with which one shall be able to determine the material constants of an orthotropic layer. The applicability of the numerical layer model-cell and the accuracy of the numerical results are confirmed by experimental results. The numerically determined material properties of the layers are used at mechanical modeling and computation of complex, layered composite structures.

Open Access: Yes

DOI: 10.12700/APH.14.2.2017.2.3

Numerical estimation method of orthotropic material properties of a roving for reinforcement of composite materials

Béla M. Csizmadia Gergely Bojtár János Égert

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2016-01-01

Volume: 13

Issue: 6

Page Range: 163-182

Description:

Knowledge of the material properties is important at machine design from composite materials. This information cannot be found in related literature and is not standard, therefore, it was necessary to determine, by measurements and by basic experiments of the mechanics of materials. This paper presents a new 3D finite element (FE) model-cell for the modeling of the material properties of a roving. By this numerical modeling method, one can determine the orthotropic and macroscopic material properties of a roving. This model-cell, models numerically, a roving, which consists of multiples of thousands of fibers that are embedded in a matrix material, as a homogenized orthotropic material. The numerical results of the material properties of the roving, can be applied to the definition of the macroscopic material properties of fiber reinforced composite laminates.

Open Access: Yes

DOI: DOI not available