Stephen Grove

Numerical simulation and experimental verification of heating performance of an integrally water-heated tool

Design and manufacturing of composite tooling are crucial in producing cost effective composite components with high quality. Aimed at identifying the optimal design of integrally heated tools in terms of their thermal performance, a number of design variables were investigated numerically in a previous study. Statistical analysis of the simulation results revealed that a parallel layout of heating channels can significantly improve the heating performance, and channel separation should be determined according to the production requirement. In the present work, an integrally water-heated tool is manufactured according to the optimal design after some geometry amendments. Thermal properties of the constituent materials of the produced tool are also measured. A numerical model of the tool geometry is simulated with actual material properties and boundary conditions to calculate the response variables of temperature uniformity and heating rate. The numerical results are verified by experimental testing, using a thermal camera and thermocouples. Good agreement between the simulation and the experimental results confirmed the suitability of numerical simulation in predicting the thermal performance of integrally heated tooling and the validity of the boundary conditions.

Bolted fibre-reinforced polymer flange joints for pipelines: A review of current practice and future challenges

Metallic bolted flanges and pipes have both been increasingly replaced by fibre-reinforced polymer materials in many applications which deal with extreme harsh environments such as oil, chemical, marine, etc. This is not only due to the fibre-reinforced polymer material’s resistance to the chemical reaction but also due to their inherent mechanical properties of high strength to weight ratio. However, very little research has been published regarding bolted flange joints made of fibre-reinforced polymer materials. Also, the availability of standards and relevant design codes are very limited for bolted fibre-reinforced polymer flange joints. Hence, the design guidelines, dimensional considerations and selection of fabrication methods for the bolted fibre-reinforced polymer flange joints have yet to be optimized fully. For instance, the ASME Boiler and Pressure Vessel Code, section X and ASME PCC-1-2013 appendix O or other similar standards do not include specific rules for the design of the bolted fibre-reinforced polymer flange joints. As a result, it is difficult to understand the consequences on the reliability of fibre-reinforced polymer flanges made with parametric variations and dimensional alterations. This has led the authors to carry out research to maximise the performance of the bolted fibre-reinforced polymer flange joints through a series of experimenters and numerical simulations. The present article will focus on the available techniques to manufacture the bolted fibre-reinforced polymer flanges along with the associated issues and possible challenges compared to metallic flanges.

Numerical analysis of the thermomechanical behaviour of an integrally water-heated tool for composite manufacturing

Integrally water-heated tooling is one of the technologies available for ‘out-of-autoclave’ processing of advanced thermoset polymer composites. Temperature variation and temperature cycling, during heating and cooling, affect the properties of tool material and may produce undesirable thermal effects that degrade the tool durability and performance, especially when the tool construction involves various materials. Hence, in the current study, the performance and the thermomechanical behaviour of an integrally water-heated tool have been investigated using finite element analysis method. The intended tool, in the current study, consists different materials of composite and metals and is designed to heat up to 90℃. Linear mechanical properties, coefficient of thermal expansions and transient heating curve of each tool part are determined experimentally and set during the numerical analysis of tool structure to calculate the static thermal load effects of deformation, stress and strain. Comparing the numerical thermal effects with the ultimate stresses and strains of the tool, materials concluded that no failure occurs with regard to static thermal loads. However, the calculated stresses are as much as the lowest magnitude of safety relates to the tool mould part made of Alepoxy.