## 2 Materials and Methods  
The experimental setup is shown in Figure 1. The experimental system consists of laser emission, temperature measurement, and surface topography measurement. The laser emission and detection system includes a millisecond pulse laser, Maler 10, spectrometer, laser energy meter, and focusing lens. The wavelength of the millisecond laser is 1064 nm, the pulse frequency is 10 Hz, the pulse width is 0.5-3 ms, and the energy is 0.5-10 J. After passing through the beam splitter, the laser is partially reflected to the probe of the energy meter, which measures the laser energy in real time to calculate the target laser energy; most of the other lasers focus on the surface of the composite through the focusing lens to damage the material. In order to measure the surface temperature of the material, a kmega high-speed thermometer and temperature probe are used to measure the temperature of the laser action area on the material surface. The time step of the thermometer is 10 \(\upmu\)s. The temperature measurement range is 350-3500 \({}^{\circ}\)C. After the laser treatment, an alicona three-dimensional surface measurement instrument was used to measure the surface damage morphology. In the experiment, the fiber/epoxy resin composite was fixed on a three-dimensional translation table, which was perpendicular to the laser. In the experiment, the surface size of the sample material is 50 \(\times\) 50 mm, 1 mm, 2 mm, or 5 mm in thickness. The fiber diameter is 0.2 mm. A composite material is usually defined as a combination of two or more different materials which have different physical and chemical properties. Thus, composite materials may possess the superior properties of both components. Generally, in the carbon fiber reinforced polymer, with fiber wrapped by the resin matrix, is the main load-bearing component of the material [13; 14]. At the same time, the resin is the load transfer element, which also plays the role of protecting the whole structure [15]. Moreover, for the physical model, based on the anisotropic structure of fiber/epoxy resin composite material, the heat conduction equation of the long-pulsed laser interacting with it can be written as follows:  
\[ \begin{array}{c}\mathrm{k_{11}}\frac{\partial^{2}\mathrm{T}}{\partial x^{2}}+ \mathrm{k_{22}}\frac{\partial^{2}\mathrm{T}}{\partial y^{2}}+\mathrm{k_{33}} \frac{\partial^{2}\mathrm{T}}{\partial x^{2}}+(\mathrm{k_{12}}+\mathrm{k_{21} })\frac{\partial^{2}\mathrm{T}}{\partial\alpha\mathrm{y}}+(\mathrm{k_{13}}+ \mathrm{k_{31}})\frac{\partial^{2}\mathrm{T}}{\partial\alpha\mathrm{z}\mathrm{ z}}\\ \hskip 14.226378 pt+(\mathrm{k_{23}}+\mathrm{k_{32}})\frac{\partial^{2}\mathrm{ T}}{\partial y\alpha\mathrm{z}}+\mathrm{Q_{L}}=\rho\mathrm{C_{P}}\frac{\mathrm{ \vartheta}\mathrm{T}(x,y,x,t)}{\mathrm{\vartheta}t}\end{array}  \tag{1}\]  
where, \(\rho\) is the density, and \(\mathrm{C_{P}}\) is the specific heat of the material, \(\mathrm{k_{ij}}\) (i, j = 1,2,3) is the thermal conductivity component of the material, and they constitute a second-order tensor \(\mathrm{k}\) :  
\[\mathrm{k}\ =\ \left| \begin{array}{ccc}\mathrm{k_{11}}&\mathrm{k_{12}}& \mathrm{k_{13}}\\ \mathrm{k_{21}}&\mathrm{k_{22}}&\mathrm{k_{23}}\\ \mathrm{k_{31}}&\mathrm{k_{32}}&\mathrm{k_{33}}\end{array}