The unidirectional carbon fiber material is commonly used in the Carbon Fiber Reinforced Plastics (CFRP). The
COMSOL Multiphysics finite element analysis software was utilized in this paper. And the 3D anisotropy model, which
based on heat conduction equation, was established to simulate the temperature field of the carbon fiber irradiated by
pulse laser. The research focused on the influences of the laser width on the material temperature field.
The thermal analysis results indicated that during the process of irradiation, the temperature field distribution of the
carbon fiber was different from the distribution of laser spot on the surface. The incident laser is Gauss laser, but the
temperature field distribution presented oval. It resulted from the heat transfer coefficient of carbon fiber was different in
the axial and in the radial. The temperature passed along the fiber axial faster than the radial.
Under the condition of the laser energy density constant, and during the laser irradiation time, the depth of the carbon
fiber temperature field increased with the pulse width increasing, and the area of the carbon fiber temperature field
increased with the pulse width increasing, However, the temperature of the laser irradiated center showed a trend of
decrease with the increasing of pulse width. The results showed that when the laser affection was constant, the laser
energy affected on the carbon fiber per unit time was increased with the decrease of the pulse width. Due to the limits of
the heat transfer coefficient of the material and laser irradiation time, the energy was injected in carbon fiber within a
short time. With the reducing of the heat conduction area, the depth and the area of the temperature field would be also
decreased. With the increase of pulse width, the time of energy injected in carbon fiber was increased, and the laser
energy affected on the carbon fiber per unit time was decrease. With the heat conduction area increasing, the depth and
area of the temperature field would be also increased. In this paper, the rule of the temperature field changing with the
pulse width was consistent with the law of conservation of energy and the heat conduction.