Pedro Herrera-franco | Centro de Investigacion Cientifica de Yucatan (original) (raw)

Papers by Pedro Herrera-franco

Polymer Composites, Jun 21, 2023

In this article authors emphasize, with solid scientific foundations, the relevance of essential ... more In this article authors emphasize, with solid scientific foundations, the relevance of essential work of fracture (EWF) to obtain fracture toughness in natural fiber reinforced composites presented on paper “Identification of micro‐failure processes of HDPE‐henequen fiber composite material by using acoustic emission monitoring: Effect of fiber surface modification” [Polymer Composites (2023)]. The significance of fiber/matrix interface adhesion relies strongly on chemical interactions, which is of great importance for composite's potential applications. Therefore, fiber surface modification implies a profound study where mechanical behavior must be characterized. Further vital information has been considered in this article to support the results on such studies.

Journal of Composite Materials, Sep 2, 2022

This paper presents a comprehensive study on the impact of surface modification of carbon fibers ... more This paper presents a comprehensive study on the impact of surface modification of carbon fibers using multiple-walled carbon nanotubes (MWCNTs) to improve the load-transfer capacity of the fiber-matrix interface of an epoxy matrix composite subjected to dynamic loads. The single-fiber fragmentation technique (SFFT) was utilized to characterize the length of interfase damage (IDL) produced by quasi-static and dynamic loadings for linear elastic and plastic strains and the residual efficiency of interfacial stress transfer. A finite element model was used to validate the optical measurement and the extent of interfase damage. Scanning electron microscopy (SEM) corroborated the presence of the MWCNTs on the surface of the carbon fibers. The interfacial shear strength (IFSS) increased by approximately 27.5%, attributed to the carbon nanotubes and a more significant fiber-matrix stress transfer. The application of dynamic loads decreased the mechanical properties of the matrix, premature fragmentation of the carbon fiber, and interfacial damage, which led to a reduction in the interfase load-transfer capacity. However, the incorporation of carbon nanotubes in the interface decreased the adverse effects generated by the application of cyclic loads, mainly the propagation of interfacial damage.

Elsevier eBooks, 2021

Abstract In this article, an overview of the earlier efforts to characterize the properties of th... more Abstract In this article, an overview of the earlier efforts to characterize the properties of the natural fiber/matrix interphase and its relevance in the control of final effective properties of a composite material is given. Because of the increasing awareness of environmental issues, natural fibers have become important and there has been a renewed and ever growing interest in their use in the development of low cost “eco-friendly” natural fiber reinforced composites. Physical, chemical and mechanical properties of naturals fibers, obtained from different sources, such as leaves, bast, fruits as well as wood-flour, have been widely studied. Their incorporation as reinforcement in the manufacture of polymeric materials (thermoplastic, thermo setting, elastomeric and more recently, biodegradable, green composites) and cementitious matrix composite materials have resulted in a great amount of work to study the physico-chemical fiber and matrix interactions and the as well as the experimental micromechanical methods for Interphase characterization. A model system, namely, henequen fiber-HDPE matrix will be used to illustrate the importance of the fiber-matrix interphase modification, the physico-chemical interactions and their characterization as well as an attempt to optimize such interphase properties and the effect on laminate mechanical properties.

Elsevier eBooks, 2011

Abstract: The effect of the interfacial fiber–matrix interactions on the mechanical performance o... more Abstract: The effect of the interfacial fiber–matrix interactions on the mechanical performance of a natural fiber reinforced thermoplastic-polymer matrix composite is reviewed. Two static testing modes are used, namely, the tensile and the shear loading modes. A well characterized fiber–matrix model system consisting of high-density polyethylene reinforced with henequen fibers (Agave fourcroydes) was selected. Special emphasis is given to the material behaviour and the state of stress for each loading, in order to better assess the fiber–matrix interface effects on the mechanical properties and failure modes.

Polymer Composites, Dec 29, 2017

Composites Part A-applied Science and Manufacturing, Mar 1, 2007

ABSTRACT The photoelastic images of the isochromatic fringes for a pull-out specimen were used to... more ABSTRACT The photoelastic images of the isochromatic fringes for a pull-out specimen were used to measure and to analyze the maximum interfacial shear strength for a thermoplastic–thermoset interface (PET/Epoxy). The photoelastic technique allows the loading process to be followed in-situ, as well as the determination of the shear stress distribution on a tested sample. A description of the stress transfer process and the measurement of the shear stress level along the embedded fiber were done. The maximum shear strength was located along the fiber surface at a distance of 2.5 times the diameter from the specimen border. The maximum shear stress values obtained from the photoelastic analysis were corrected to include the tri-dimensional axisymmetric distribution of the shear stress around the fiber. The corrected shear stress measured τcMax ranged from 0.27 to 1.17 MPa.

Express Polymer Letters, 2017

Journal of Applied Polymer Science, 2006

American Society of Composites - 30th Technical Conference, Nov 2, 2015

The science of materials has witnessed a notorious development of composite materials using nano-... more The science of materials has witnessed a notorious development of composite materials using nano-scale reinforcements such as nano-tubes, nano-flakes, or nano-fibers, all with promising exceptional mechanical properties. However, when these composites have been used to replace advanced fiber reinforced composites materials in certain applications, the results have been poor or definitively insufficient. An approach proposed to take advantages of the nano-scale material outstanding properties is their use in hierarchical composite materials, that is, in multi-scale composites materials. The use of the single-fiber fragmentation test to measure the IFFS is analyzed in this paper considering the presence of the nano-reinforcement material in the hierarchical composite material. A parametric study of the stress distribution for a monofilament carbon fiber whose surface is modified with carbon nanotubes (CNT) and embedded in an epoxy resin is first discussed. The analysis at two different scales, nano- and micro-scales and the stress interactions between them was necessary. For this purpose, concepts of the mechanics of a heterogeneous media, specifically the Mori-Tanaka Methods was used for the nano-scale interactions. The finite element method was used for the micro-scale. The linear elastic results reveal that, when the CNT are present in the carbon fiber-surface, contribute to a better stress distribution along the fiber-matrix interface once the fiberfragmentation process is started. However, the presence of the CNT may contribute to the appearance of large stress concentrations in the surrounding matrix, especially when the CNTs are randomly oriented. An attempt to establish relationships between the stress-transfer behavior and the physico-chemical interactions is made.

Macromolecular Symposia, Sep 1, 2004

Polymer Composites, Apr 1, 2004

Journal of Applied Polymer Science, Aug 20, 1991

... Article. Physical and mechanical properties of henequen fibers. MN Cazaurang-Martinez,; PJ He... more ... Article. Physical and mechanical properties of henequen fibers. MN Cazaurang-Martinez,; PJ Herrera-Franco,; PI Gonzalez-Chi,; M. Aguilar-Vega. Article first published online: 10 MAR 2003. DOI: 10.1002/app.1991.070430412. Copyright © 1991 John Wiley &amp; Sons, Inc. Issue. ...

Publisher Summary Natural fibres are important because of the renewed interest in their use in th... more Publisher Summary Natural fibres are important because of the renewed interest in their use in the development of low-cost eco-friendly natural-fibre composites. The mechanical properties of natural fibres containing cellulose in composite materials are the subject of current international research efforts. This is especially important if such fibres are residues of agro industrial processes and if their raw properties are acceptable for composites, making their purification to pure cellulose unnecessary. The advent and widely expanding use of composite materials in more demanding applications, such as highly loaded structures, have forced a continuous revision of the subject of mechanical testing. That has resulted in the development of new test methods and the existing techniques continuously verified and re-examined. The principal difficulty arising in the testing of composites has also arisen when testing Natural-Fibre Reinforced Composites (NFRC) because of the inherent variability of the geometrical, physical and mechanical properties of this type of fibre. This chapter discusses the mechanical characterization of a natural-fibre reinforced thermoplastic-polymer matrix composite under testing modes such as tensile, compressive, flexural and shear. For this purpose, a model system consisting of High-Density Polyethylene (HDPE) reinforced with henequen fibres was selected. Several studies have been conducted in the past few years for the fibre-matrix system and a detailed experimental program has been conducted to measure fibre-matrix adhesion, to determine interfacial chemistry and material properties, as well as the fibre-matrix interfacial failure model.