Numerical simulation of laser machining of carbon-fibre-reinforced composites

Abstract

The growing use of carbon-fibre-reinforced polymer (CFRP) composites as high-performance lightweight materials in aerospace and automotive industries demands efficient and low-cost machining technologies. The use of laser machining for cutting and drilling composites is attractive owing to its high speed, flexibility, and ease of automation. However, the anisotropic material properties of composites, and issues related to the heat-affected zone (HAZ), charring, and potential delamination during laser processing, are major obstacles in its industrial applications. In order to improve the quality and dimensional accuracy of CFRP laser machining, it is important to understand the mechanism of the transient thermal behaviour and its effect on material removal. Based on the ‘element death’ technique of the finite element (FE) method, a three-dimensional model for simulating the transient temperature field and subsequent material removal has been developed, for the first time, on a heterogeneous fibre—matrix mesh. In addition to the transient temperature field, the model also predicts the dimensions of the HAZ during the laser machining process. Experimental results obtained with same process variables using a 355 nm DPSS Nd:YVO4 laser were used to validate the model. Based on the investigation, the mechanism of material removal in laser composite machining is proposed. The results suggest that the employed FE approach can be used to simulate pulsed laser cutting of fibre-reinforced polymer composites.

Laser-based surface preparation of composite laminates leads to improved electrodes for electrical measurements

“…Once the temperature reaches the vaporization temperature of the matrix, the matrix along the conduction path evaporates. This zone where the matrix loss occurs due to photothermal conduction is known as the heat-affected zone (HAZ) [52]. It has been shown that the size of the HAZ depends on the laser scanning speed, direction, power and frequency as these variables determine the energy absorbed into the material [52,30].…”

“…This zone where the matrix loss occurs due to photothermal conduction is known as the heat-affected zone (HAZ) [52]. It has been shown that the size of the HAZ depends on the laser scanning speed, direction, power and frequency as these variables determine the energy absorbed into the material [52,30]. Figure 8 also shows optical images taken from three selected regions that are representative of the three groups mentioned above.…”

High-power picosecond laser drilling/machining of carbon fibre-reinforced polymer (CFRP) composites

“…The influence of different process parameters including laser wavelengths, beam transverse mode, pulse duration, repetition rate, laser power density, fluence (energy density), beam spot size, scanning speed and machining strategy were investigated [5,[9][10][11][12][13][14][15][16][17][18][19][20][21]. Li et al [9] investigated the machining quality of CFRP using a diode-pumped solidstate UV laser.…”

TEA CO2 laser machining of CFRP composite

“…Consequently, it is considered as a critical quality parameter in assessing the quality of the laser cutting of CFRP composites in this work. The large difference in thermal properties between the two constituent materials of CFRP composites results in excessive heat-affected zones [10]. This is considered as the major obstacle for wide industry applications of laser machining of CFRP composites.…”

“…They showed that minimum HAZ (around 30-50 lm) can be obtained using a nanosecond pulsed UV laser. Negarestani et al [10] developed a three-dimensional model to simulate the transient temperature field and subsequent material removal on a heterogeneous fibre-matrix mesh in laser machining of CFRP composite. They predicted the dimensions of the HAZ during laser machining of CFRP.…”