木工超薄圆锯片激光冲击适张预应力场的生成与调控机理

Tensioning is an important process in the manufacturing of woodworking circular saw blade for produce a reasonable pre-stress field inside the circular saw blade. With the production and wide application of woodworking ultra-thin circular saw blade, it is necessary to produce and accurately control the pre-stress field of the saw blade, which is a scientific and technical problem need to be solved urgently. Therefore, laser shock tensioning process is proposed in this project. The high pressure plasma shock wave generated by the strong laser beam is applied to the local areas of circular saw blade and local plastic deformation is produced to the saw blade. And then the pre-stress field is generated in the saw blade with the tensioning effect. X-ray stress detector is used in this project for measuring the pre-stress field of the saw blade after laser shock tensioning process. The elastic plastic simulation model for laser shock tensioning process is built by nonlinear finite element method in this project. The formation mechanism of the pre-stress field is revealed and the influence law and regulation mechanism of shock area distribution, laser energy, laser spot diameter, pulse width, shock times and other technological parameters on the pre-stress field are explored, which can provide theory evidence and key technical parameters for laser shock tensioning process. The research results have important significance for the realization of high efficiency, accuracy and green tensioning, improving the manufacturing technology level of ultra-thin circular saw blade, the utilization ratio and processing precision of wood.

适张是木工圆锯片在生产制造过程中的重要工艺环节，目的是使其内部产生合理的预应力场。随着木工超薄圆锯片的生产制造和广泛应用，对其适张工艺的要求越来越高，如何生成并精确调控锯片的预应力场是迫切需要解决的科学技术问题。为此，本项目提出激光冲击适张工艺，利用强激光束产生的高压等离子体冲击波作用于锯片局部区域，使其产生局部塑性变形进而生成预应力场，产生适张效果。本项目采用X射线应力检测仪对锯片激光冲击适张后的预应力场进行实测，利用非线性有限元法建立锯片激光冲击适张过程的弹塑性仿真模型，揭示锯片激光冲击适张预应力场的生成机理，探索冲击点分布状态及激光能量、光斑直径、脉宽、冲击次数等工艺参数对于锯片预应力场的影响规律及调控机制，为激光冲击适张工艺提供理论依据和关键技术参数。研究成果对实现高效率高精度绿色化适张、提高木工超薄圆锯片制造工艺水平、木材加工利用率和锯切精度等具有重要意义。

适张是圆锯片在生产制造过程中的重要工艺环节，目的是使其内部产生合理的预应力场。随着超薄圆锯片的生产制造和广泛应用，对其适张工艺的要求越来越高，如何生成并精确调控锯片的预应力场是迫切需要解决的科学技术问题。.本项目结合激光冲击波理论、弹塑性力学理论、振动模态分析理论以及非线性有限元法，通过ABAQUS非线性有限元仿真分析平台，建立了集弹塑性、振动模态分析于一体的圆锯片激光冲击适张过程仿真模型，实现了圆锯片激光冲击适张后预应力场与固有频率的理论分析；本项目利用激光冲击设备、静态应力应变采集装置、力锤固有频率测试系统，测试分析了圆锯片激光冲击适张预应力场、固有频率的演变规律，分析了激光能量、光斑直径、脉宽等工艺参数对于预应力场与固有频率的影响机制，阐明了圆锯片激光冲击适张预应力场的生成与调控机理。.理论与试验结果表明：圆锯片激光冲击后，外缘生成了一定量级的切向拉应力，具有适张效果；通过调整激光冲击区域的大小、位置以及分布形式，能够对圆锯片外缘的切向拉应力数值进行有效调控；经工艺优化，圆锯片（直径200-300mm）激光冲击适张的关键技术参数如下：激光能量30J，脉宽20ns，光斑直径3mm，冲击区半径10-16mm，环向冲击区个数8-10个，径向冲击区个数2个。.研究成果对实现高效率高精度绿色化适张、提高木工超薄圆锯片制造工艺水平、木材加工利用率和锯切精度等具有重要意义。