Die and post-die temperature and cure in graphite/epoxy composites

Valliappan, Meyyappan; Roux, J. A.; Vaughan, J. G.; Arafat, E. S.

doi:10.1016/1359-8368(95)00001-1

Cited by 64 publications

(106 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A schematic representation of the calculation procedure is depicted in Figure 7. It is trivial to outline that, in correspondence with the external radius, the radial solicitation equals to the opposite of the pressure acting on the die internal wall, allowing one to derive the frictional contribution using (6).…”

Section: Semianalytical Analysis Of Distortions and Pressurementioning

confidence: 99%

“…As a consequence, the whole temperature field is established solving a unique nonlinear equation using the lumped material properties [4][5][6][7][8][9][10][11][16][17][18], which can be written as follows:…”

Section: Continuous Modelmentioning

confidence: 99%

“…Several researchers have performed numerical and experimental investigations on different aspects inherent to the pultrusion process, mainly focusing on issues related to heat transfer and cure [5][6][7][8][9][10][11], pressure distribution [12,13], and pulling force [14][15][16][17][18][19][20]. However, proposed models often neglect the interactions between involved phenomena, on the base of some simplifying assumptions.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Computational Approaches for Modeling the Multiphysics in Pultrusion Process

Carlone

Baran

Hattel

et al. 2013

Advances in Mechanical Engineering

View full text Add to dashboard Cite

Pultrusion is a continuous manufacturing process used to produce high strength composite profiles with constant cross section. The mutual interactions between heat transfer, resin flow and cure reaction, variation in the material properties, and stress/distortion evolutions strongly affect the process dynamics together with the mechanical properties and the geometrical precision of the final product. In the present work, pultrusion process simulations are performed for a unidirectional (UD) graphite/epoxy composite rod including several processing physics, such as fluid flow, heat transfer, chemical reaction, and solid mechanics. The pressure increase and the resin flow at the tapered inlet of the die are calculated by means of a computational fluid dynamics (CFD) finite volume model. Several models, based on different homogenization levels and solution schemes, are proposed and compared for the evaluation of the temperature and the degree of cure distributions inside the heating die and at the postdie region. The transient stresses, distortions, and pull force are predicted using a sequentially coupled three-dimensional (3D) thermochemical analysis together with a 2D plane strain mechanical analysis using the finite element method and compared with results obtained from a semianalytical approach.

show abstract

Section: Semianalytical Analysis Of Distortions and Pressurementioning

confidence: 99%

Section: Continuous Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Computational Approaches for Modeling the Multiphysics in Pultrusion Process

Carlone

Baran

Hattel

et al. 2013

Advances in Mechanical Engineering

View full text Add to dashboard Cite

show abstract

“…This method was found to be reliable for solving the related governing equations of resin flow, cure and heat transfer. Valliappan et al [6] also developed a numerical model using a fixed control-volume based on finite-different approach to predict the die and post-die temperature, and degree of cure of a graphite/epoxy pultruded composite with cylindrical shape geometry. Pull speed, die-wall temperature setting and fibre volume fraction, were considered as processing variables.…”

Section: Numerical Models Applied To the Optimisation Of Pultrusion Pmentioning

confidence: 99%

“…After exothermic peak, the composite starts losing heat to the die wall through conduction as it proceeds along the die, and through convection and radiation to the surrounding environment upon exiting the die. Therefore, the TP in the composite material inside the forming die is a balance of heat transfer, generated by heating die system and exothermic reaction of resin matrix [5,6].…”

Section: Introductionmentioning

confidence: 99%

Optimising the energy consumption on pultrusion process

Silva

Ferreira

Ribeiro

et al. 2014

Composites Part B: Engineering

View full text Add to dashboard Cite

a b s t r a c tThis study is based on a previous experimental work in which embedded cylindrical heaters were applied to a pultrusion machine die, and resultant energetic performance compared with that achieved with the former heating system based on planar resistances. The previous work allowed to conclude that the use of embedded resistances enhances significantly the energetic performance of pultrusion process, leading to 57% decrease of energy consumption. However, the aforementioned study was developed with basis on an existing pultrusion die, which only allowed a single relative position for the heaters.In the present work, new relative positions for the heaters were investigated in order to optimise heat distribution process and energy consumption. Finite Elements Analysis was applied as an efficient tool to identify the best relative position of the heaters into the die, taking into account the usual parameters involved in the process and the control system already tested in the previous study. The analysis was firstly developed based on eight cylindrical heaters located in four different location plans. In a second phase, in order to refine the results, a new approach was adopted using sixteen heaters with the same total power. Final results allow to conclude that the correct positioning of the heaters can contribute to about 10% of energy consumption reduction, decreasing the production costs and leading to a better eco-efficiency of pultrusion process.

show abstract

Simultaneous optimization of die‐heating and pull‐speed in pultrusion of thermosetting composites

Joshi

2003

Polymer Composites

View full text Add to dashboard Cite

Die‐temperature and pull‐speed are the key parameters in pultrusion that affect the degree and uniformity of the curing of thermosetting composites, which in turn influence their mechanical properties and in‐service performance. This paper presents the development, implementation, and validation of a numerical procedure for arriving at an optimum combination of die‐heater temperatures and pull‐speed for producing a uniformly cured composite pultrudate. An objective function representing the effects of both parameters on the distribution of degree‐of‐cure across the cross section of a pultruded part at the die exit was established. The function was used to develop an algorithm for calculating the required changes in die‐heater temperatures and pull‐speed to achieve a desirable degree‐of‐cure with maximum possible uniformity. The algorithm was implemented using the three‐dimensional. Finite Element/Nodal Control Volume (FE/NCV) approach for process simlation, in which a general‐purpose FE package was used to perform heat transfer analysis, together with other routines developed to perform cure modeling and the optimization. The application of the developed procedure was demonstrated by simulating pultrusion of a graphite/epoxy C‐section. The results of the studies show that the procedure is numerically stable and works well for a die with multiple heaters.

show abstract

Die and post-die temperature and cure in graphite/epoxy composites

Cited by 64 publications

References 2 publications

Computational Approaches for Modeling the Multiphysics in Pultrusion Process

Computational Approaches for Modeling the Multiphysics in Pultrusion Process

Optimising the energy consumption on pultrusion process

Simultaneous optimization of die‐heating and pull‐speed in pultrusion of thermosetting composites

Contact Info

Product

Resources

About