Novel coupon geometry for tensile property determination of Sheet Molding Compounds

Burgoa

Lekube

et al. 2022

Self Cite

Sheet molding compounds (SMCs) are interesting materials for the hybrid and electric vehicle (HEV) industry due to their high stiffness‐weight ratio, ease of processing, and competitive costs. Nevertheless, HEV industry demands advanced requirements such as enhanced vibration damping capabilities and thermal fatigue resistance. In this regard, the high stiffness of SMCs usually involves poor damping capacity, so improving the vibration damping behavior on SMCs proves to be a growing research line. The hybridization of SMCs with thermoplastic elastomers (TPEs), by means of free‐layer damping structures, has been confirmed as an effective way to enhance the damping properties of SMCs, but these structures lack the sufficient temperature resistance for certain applications. In this work, the hybridization of epoxy‐based carbon fiber SMC with TPE by sandwich structures has been studied as an innovative strategy to address the enhancement of the vibration damping capacities of SMCs and assure their usage on temperature applications. The mechanical properties, vibration damping performance, and influence of temperature of the sandwich structures has been analyzed by quasi‐static 3‐point bending tests and dynamic mechanical analysis. Experimental tests show the capability of hybrid sandwich structures to boost the vibration damping efficiency of SMCs while keeping their suitability for structural applications.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Improvement of structural vibration damping performance of SMCs through SMC/TPE sandwich structures

Burgoa

Lekube

et al. 2022

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“…SMCs represent a highly versatile alternative to traditional materials used in many structural automotive components because they present an outstanding compromise between the high stiffness of continuous fiber reinforced composites and the formability of short fiber reinforced composites. [4][5][6] SMC components are characterized by high glass transition (T g ) values and so a relatively poor vibration damping performance at around room temperature. [7][8][9] Then, when operating at this temperature, the vibration of SMC structures would lead to detrimental effects such as noise, dynamic stresses that shorten the structural fatigue life and reduced performance.…”

Section: Introductionmentioning

confidence: 99%

“…Among different types of FRP, sheet molding compounds (SMCs), which are discontinuous fiber reinforced composites based on thermoset resins, are gaining significant attention in many advanced lightweight designs. SMCs represent a highly versatile alternative to traditional materials used in many structural automotive components because they present an outstanding compromise between the high stiffness of continuous fiber reinforced composites and the formability of short fiber reinforced composites 4–6 …”

Section: Introductionmentioning

confidence: 99%

SMC/TPE bi‐layer configurations for structural vibration damping applications

Burgoa

Lekube

2021

Self Cite

Sheet molding compounds (SMCs) have considerable potential as lightweight alternative to traditional materials used in automotive components. However, despite their outstanding mechanical properties, their vibration damping characteristics are often relatively poor for several applications. Therefore, enhancing the vibration damping capability of SMCs represents a field with increasing interest. Application of viscoelastic layers to high stiffness materials, such as SMCs, represents an effective approach to add vibration damping functionalities to lightweight structural components. In this work, the incorporation of thermoplastic elastomers (TPEs) is studied as a novel strategy to enhance the structural vibration damping capability of SMCs. Several types of SMC and TPEs have been considered and the effect of TPE‐SMC thickness ratio on the damping and stiffness properties is investigated. The viscoelastic properties and vibration damping performance were evaluated by dynamic mechanical analysis. The effect of TPE addition on stiffness was studied by three‐point bending. Results reveal the potential of the incorporation of thin TPE layers as cost‐effective strategy to enlarge the vibration damping efficiency of SMCs while maintaining their overall high stiffness. It is expected that the bi‐material configurations presented in the current study will contribute to advance the development of new lightweight multi‐functional solutions for modern transport applications.

“…Sheet molding compounds (SMC) are composite materials, based on a thermoset system (usually composed by a thermoset resin such as polyester, vinyl ester or epoxy, and combined with fillers) 1 and reinforced with discontinuous glass or carbon fibers, which are becoming key players on transport-related industries due to their outstanding compromise between processability and high mechanical properties. [2][3][4][5] As its name indicates, these pre-impregnated materials are manufactured on readyto-mold sheets and the compression molding is the main transformation process to convert them into structural or sub-structural components. 6,7 The compression molding process enables the manufacturing of high complexity shapes at low cycle times 8 with the employment of simple and cost affordable tools compared with other manufacturing processes.…”

Section: Introductionmentioning

confidence: 99%

An evaluation of the curing characteristics of thermosetting epoxy carbon fiber sheet molding compounds and validation through computer simulations and molding trials

Arrillaga

Stelzer

et al. 2021

Self Cite

Sheet molding compounds (SMC) are ready-to-mold thermoset composite materials reinforced with discontinuous fibers, usually compression molded.Finite element (FE) based compression molding tools can be employed to optimize this process; FE tools require to define material models using raw material data measured through different characterization techniques. In this study, the cure kinetics of an epoxy-based carbon fiber SMC has been characterized by means of differential scanning calorimetry (DSC) and moving die rheometer (MDR) techniques. Based on these datasets, Claxton-Liska and Kamal-Souror models have been set and the compression molding of a validation plate was performed, both experimentally and virtually. The results indicate that, even if both characterization techniques are valid for SMC curing characterization, MDR technique enables the characterization of the material at real molding temperatures and the model based on MDR leads to more accurate results.