Research Papers

Bondline Temperature Control for Joining Composites With an Embedded Heater

[+] Author and Article Information
Brandon P. Smith, Mahdi Ashrafi, Mark E. Tuttle, Santosh Devasia

Department of Mechanical Engineering,
University of Washington,
Seattle, WA 98195

Contributed by the Manufacturing Engineering Division of ASME for publication in the JOURNAL OF MANUFACTURING SCIENCE AND ENGINEERING. Manuscript received February 5, 2015; final manuscript received July 2, 2015; published online September 9, 2015. Editor: Y. Lawrence Yao.

J. Manuf. Sci. Eng 138(2), 021011 (Sep 09, 2015) (9 pages) Paper No: MANU-15-1073; doi: 10.1115/1.4031069 History: Received February 05, 2015

This paper applies estimation and control techniques to achieve the desired bondline temperature for out-of-autoclave, adhesive bonding of carbon-fiber composite components. Rather than heating the entire system to cure the adhesive, e.g., in an autoclave, this research uses controlled heating targeted at the bondline with an embedded heater. The main contribution of this work is control using estimates of the bondline temperature without embedded sensors and wiring (of materials not intrinsic to the system) that can lead to reduced bond strength. Sensors placed outside the bond region are used to accurately estimate the bondline temperature to within 2% of the temperature range over which the bondline temperature is changed. Experimental results show that the estimated temperature can be used with feedback to achieve the desired, bondline, time–temperature profile that is needed to cure the adhesive. Additionally, shear lap joint tensile tests show that the resulting joint strength is comparable to specimens bonded using an external heat blanket.

Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.


Roeseler, W. G. , Sarh, B. , Kismarton, M. , Quinlivan, J. , Sutter, J. , and Roberts, D. , 2007, “Composite Structures: The First 100 Years,” 16th International Conference on Composite Materials, Kyoto, Japan, July 8–13, pp. 1–10.
Egan, B. , McCarthy, C. , McCarthy, M. , Gray, P. , and O'Higgins, R. , 2013, “Static and High-Rate Loading of Single and Multi-Bolt Carbon–Epoxy Aircraft Fuselage Joints,” Composites, Part A, 53, pp. 97–108. [CrossRef]
Pearce, G. M. , Johnson, A. F. , Thomson, R. S. , and Kelly, D. W. , 2010, “Experimental Investigation of Dynamically Loaded Bolted Joints in Carbon Fibre Composite Structures,” Appl. Compos. Mater., 17(3), pp. 271–291. [CrossRef]
Abdelal, G. F. , Georgiou, G. , Cooper, J. , Robotham, A. , Levers, A. , and Lunt, P. , 2015, “Numerical and Experimental Investigation of Aircraft Panel Deformations During Riveting Process,” ASME J. Manuf. Sci. Eng., 137(1), p. 011009. [CrossRef]
Che, D. , Saxena, I. , Han, P. , Guo, P. , and Ehmann, K. F. , 2014, “Machining of Carbon Fiber Reinforced Plastics/Polymers: A Literature Review,” ASME J. Manuf. Sci. Eng., 136(3), p. 034001. [CrossRef]
Baldan, A. , 2004, “Adhesively-Bonded Joints and Repairs in Metallic Alloys, Polymers and Composite Materials: Adhesives, Adhesion Theories and Surface Pretreatment,” J. Mater. Sci., 39(1), pp. 1–49. [CrossRef]
Banea, M. D. , and da Silva, L. F. M. , 2009, “Adhesively Bonded Joints in Composite Materials: An Overview,” Proc. Inst. Mech. Eng., Part L, 223(1), pp. 1–18 .
Seaton, C. , and Richter, S. , 2014, “Nonconforming Composite Repairs: Case Study Analysis,” William J. Hughes Technical Center, Federal Aviation Administration, Washington, DC, Technical Report No. DOT/FAA/TC-14/20.
Sato, M. , Yokobori, A. T. , Ozawa, Y. , Kamiyama, T. , Miyanaga, T. , Beaumont, P. W. R. , and Sekine, H. , 2002, “Experimental Study of Repair Efficiency for Single-Sided Composite Patches Bonded to Aircraft Structural Panels,” Adv. Compos. Mater., 11(1), pp. 51–59. [CrossRef]
Ashrafi, M. , Devasia, S. , and Tuttle, M. , 2015, “Resistive Embedded Heating for Homogeneous Curing of Adhesively Bonded Joints,” Int. J. Adhes. Adhes., 57, pp. 34–39. [CrossRef]
Ramakrishnan, B. , Zhu, L. , and Pitchumani, R. , 1999, “Curing of Composites Using Internal Resistive Heating,” ASME J. Manuf. Sci. Eng., 122(1), pp. 124–131 . [CrossRef]
Zhu, L. , and Pitchumani, R. , 2000, “Analysis of a Process for Curing Composites by the Use of Embedded Resistive Heating Elements,” Compos. Sci. Technol., 60(14), pp. 2699–2712. [CrossRef]
Santos, C. , Plaisted, T. , Arbelaez, D. , and Nemat-Nasser, S. , 2004, “Modeling and Testing of Temperature Behavior and Resistive Heating in a Multifunctional Composite,” Proc. SPIE, 5387, pp. 24–26.
Joseph, C. , and Viney, C. , 2000, “Electrical Resistance Curing of Carbon-Fibre/Epoxy Composites,” Compos. Sci. Technol., 60(2), pp. 315–319. [CrossRef]
Rider, A. , Wang, C. , and Cao, J. , 2011, “Internal Resistance Heating for Homogeneous Curing of Adhesively Bonded Repairs,” Int. J. Adhes. Adhes., 31(3), pp. 168–176. [CrossRef]
Mas, B. , Fernndez-Blzquez, J. P. , Duval, J. , Bunyan, H. , and Vilatela, J. J. , 2013, “Thermoset Curing Through Joule Heating of Nanocarbons for Composite Manufacture, Repair and Soldering,” Carbon, 63, pp. 523–529. [CrossRef]
Sung, P.-C. , and Chang, S.-C. , 2015, “The Adhesive Bonding With Buckypaper–Carbon Nanotube/Epoxy Composite Adhesives Cured by Joule Heating,” Carbon, 91, pp. 215–223. [CrossRef]
Twardowski, T. , Lin, S. , and Geil, P. , 1993, “Curing in Thick Composite Laminates: Experiment and Simulation,” J. Compos. Mater., 27(3), pp. 216–250. [CrossRef]
Parthasarathy, S. , Mantell, S. , and Stelson, K. , 2004, “Estimation, Control and Optimization of Curing in Thick-Sectioned Composite Parts,” ASME J. Dyn. Syst., Meas., Control, 126(4), pp. 824–833. [CrossRef]
Rai, N. , and Pitchumani, R. , 1997, “Rapid Cure Simulation Using Artificial Neural Networks,” Composites, Part A, 28(9–10), pp. 847–859. [CrossRef]
Papathanasiou, T. K. , Markolefas, S. I. , Filopoulos, S. P. , and Tsamasphyros, G. J. , 2010, “Heat Transfer in Thin Multilayered Plates—Part II: Applications to the Composite Patch Repair Technique,” ASME J. Heat Transfer, 133(2), p. 021303 . [CrossRef]
Emery, A. , 2010, “Preliminary Results for Estimating the Backside Heat Losses of a Composite Panel,” ASME Paper No. IHTC14-23226.
Nightingale, C. , and Day, R. J. , 2002, “Flexural and Interlaminar Shear Strength Properties of Carbon Fibre/Epoxy Composites Cured Thermally and With Microwave Radiation,” Composites, Part A, 33(7), pp. 1021–1030. [CrossRef]
Tanrattanakul, V. , and Jaroendee, D. , 2006, “Comparison Between Microwave and Thermal Curing of Glass Fiber–Epoxy Composites: Effect of Microwave-Heating Cycle on Mechanical Properties,” J. Appl. Polym. Sci., 102(2), pp. 1059–1070. [CrossRef]
Mahdi, S. , Kim, H. , Gama, B. , Yarlagadda, S. , and Gillespie, J. , 2003, “A Comparison of Oven-Cured and Induction-Cured Adhesively Bonded Composite Joints,” J. Compos. Mater., 37(6), pp. 519–542. [CrossRef]
Ahmed, T. , Stavrov, D. , Bersee, H. , and Beukers, A. , 2006, “Induction Welding of Thermoplastic Composites—An Overview,” Composites, Part A, 37(10), pp. 1638–1651. [CrossRef]
Ogata, K. , 1995, Discrete-Time Control Systems, Vol. 8, Prentice-Hall, Englewood Cliffs, NJ.
Bergman, T. , and Incropera, F. , 2011, Fundamentals of Heat and Mass Transfer, Wiley, Hoboken, NJ.
Windhorst, T. , and Blount, G. , 1997, “Carbon–Carbon Composites: A Summary of Recent Developments and Applications,” Mater. Des., 18(1), pp. 11–15. [CrossRef]
Edie, D. , 1998, “The Effect of Processing on the Structure and Properties of Carbon Fibers,” Carbon, 36(4), pp. 345–362. [CrossRef]
Welch, B. L. , 1947, “The Generalization of ‘Student's’ Problem When Several Different Population Variances Are Involved,” Biometrika, 34(1–2), pp. 28–35 . [PubMed]


Grahic Jump Location
Fig. 4

Open-loop step response Ti of the thermal system: (dotted line) response of fitted model GT,i in Eq. (2) and (solid line) experimentally measured

Grahic Jump Location
Fig. 3

Schematic of experimental system (without bonding) for controller and estimator design. The structural-film adhesive in Fig. 1 is replaced with Teflon insulating sheets to prevent adhesive bonding during experimental estimation of model parameters. The entire system is still under vacuum pressure as in the joining case.

Grahic Jump Location
Fig. 2

The desired temperature profile Ti,d at the bondline, as recommended by the adhesive manufacturer. Note that the initial value Ti,d(0) at time t = 0 is room temperature, which depends on the experimental conditions.

Grahic Jump Location
Fig. 1

Schematic of experimental system during joining. An embedded heater is used to cure the structural-film adhesive, which bonds two carbon-fiber composite adherends. The entire system is insulated and is under vacuum pressure.

Grahic Jump Location
Fig. 5

Block diagram of control scheme when a sensor is available to measure the inner bondline temperature Ti

Grahic Jump Location
Fig. 6

Schematic of the discrete-time implementation of the controller (C(z) in Eq. (18)) with a saturation block

Grahic Jump Location
Fig. 7

Schematic of temperature model through adherend

Grahic Jump Location
Fig. 8

Results of step response as in Fig. 4 for (a) the measured temperatures (inner bondline temperature Ti and outer temperatures To and T1) and the estimated temperature Ti,e calculated from Eq. (22), and (b) the error eE in the fit from Eq. (28)

Grahic Jump Location
Fig. 9

RMS value of the error eE in the estimated temperature Ti,e due to variations in the parameters p1 = k1, p2=ka, and p3=ρLcp

Grahic Jump Location
Fig. 10

Block diagram of control system during joining. The inner bondline temperature Ti  is controlled using the estimated inner bondline temperature Ti,e.

Grahic Jump Location
Fig. 11

Experimental results with cure profile without adhesive with (a) measured inner bondline temperature Ti, estimated inner temperature Ti,e, and desired inner temperature Ti,d with the control as in Fig. 10, (b) estimator error eE  as in Eq. (28), and (c) tracking error ed as in Eq. (38)

Grahic Jump Location
Fig. 12

Photo of the experimental setup during bonding with the ERH

Grahic Jump Location
Fig. 13

Experimental results with cure profile during bonding with adhesive with (a) measured inner bondline temperature Ti, estimated inner temperature Ti,e, and desired inner temperature Ti,d, (b) estimator error eE as in Eq. (28), and (c) tracking error ed as in Eq. (38)

Grahic Jump Location
Fig. 14

Temperature profiles for bonding with (a) an embedded heater, (b) an external heat blanket with fabric in the bondline, and (c) an external heat blanket without fabric in the bondline

Grahic Jump Location
Fig. 15

Schematic of bonding with Heatcon HB with external heater

Grahic Jump Location
Fig. 16

Schematic of specimens cut from single lap joint cut for tensile testing with top view (left), and side view after adding tabs (right)

Grahic Jump Location
Fig. 17

Mean tensile test load at failure for single lap joints made with an ERH, HB without embedded fabric, and HB with embedded fabric, all with one standard deviation error bars




Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In