Cutting is the primary method of material removal, and the quality of machined parts depends on the geometry of cutting tools. In this paper, a new cutting force coefficient model is established, revealing the influence of cutting-edge radius on the cutting process. The effects of cutting-edge radius on the shear angle and cutting force components are analyzed by finite element simulations. A series of simulations is conducted, and the results show that with increased cutting-edge radius, the shear angle decreases nonlinearly, and the cutting force increases gradually. Additionally, the growth rate of the feed force caused by increasing the cutting-edge radius is higher than that of the tangential force. Furthermore, the stress concentration area of the machined surface extends from the surface to the subsurface as the cutting-edge radius increases. The results of this research show that changing the cutting edge affects the cutting force component, shear angle, and stress concentration range during the cutting process. These results provide a theoretical reference for predicting the residual stress in parts.

Touch-trigger probes (TTPs) have been commonly utilized in on-machine measurement (OMM) by virtue of their low cost and high repeatability. The pre-travel error (PTE) compensation of the probe is one of the critical issues in improving OMM precision. The majority of existing studies on PTE compensation in five-axis OMM adopt the same strategy as in three-axis OMM. Thus, the discrepancies between the two measurement processes and PTE compensation principles are ignored, which results in poor compensation accuracy for the five-axis measured results. In this paper, a novel PTE compensation strategy is presented to accurately compensate for the five-axis OMM results. Due to the limitations of the PTE map formed by the calibrated positions on the standard sphere for application in five-axis measurement, a PTE map represented by the touch positions on the stylus tip is developed. As a result, the exact mapping relationships between the touch positions on the stylus tip and the PTEs in five-axis OMM can be constructed. Then, the calculations of the PTE compensation component (PTECC) in three-axis OMM and five-axis OMM are discussed and compared. Specially, the positioning deviations of rotary axes are also considered in the proposed strategy to compensate for their influence on the measured results during the five-axis measurement. Finally, impeller inspection tests are performed to validate the effectiveness of the proposed compensation strategy for five-axis OMM, and more than 20% inspection precision improvement is observed.

Cutter edge temperature in milling is an important factor to cutter life. With high cutting speed and feedrate, the cutting efficiency is high; however, the cutter edge temperature is high, shortening the cutter life. Therefore, it is necessary to know the cutter edge temperature in milling. Unfortunately, the cutter edge temperature is difficult to measure and predict in milling. To address the technical challenge, an analytical approach was proposed to predict cutter edge temperature in milling. First, the heat flux into the cutter edge was calculated. Second, by using the Green function, the cutter edge temperature was figured out, and the results obtained from this approach agreed well with that of a recognized test. Then, based on the engagement between the cutter and workpiece in trochoidal milling, the cutter edge temperature was obtained in trochoidal milling. Finally, a temperature comparison was made between trochoidal and side milling based on this analytical approach, and the reasons that trochoidal machining could extend the cutter life were found. This approach is first proposed to calculate the cutter edge temperature in trochoidal milling and can be applied to machining parameters optimization in trochoidal milling and cutter design optimization.

Purpose: The purpose of this paper is to find a method for key assembly structure identification in complex mechanical assembly. Three-dimensional model reuse plays an increasingly important role in complex product design and innovative design. Assembly model has become important resource of models reuse in enterprises, which contains certain function assembly structures. These assembly structures implicating plenty of design intent and design experience knowledge can be used to support function-structure design, modular design reuse and semantics analysis for complex product. Design/methodology/approach: A method for identifying key assembly structures in assembly model is presented from the viewpoint of assembly topology and multi-source attributes. First, assembly model is represented based on complex network. Then, a two-level evaluation model is put forward to evaluate importance of parts assembled, and the key function parts in assembly can be obtained. After that, on the basis of the function parts, a heuristic algorithm upon breadth first searching is given to identify key assembly structures. Findings: The method could be used to evaluate key function parts and identify key assembly structures in complex mechanical assembly according to the specific circumstances. Practical implications: The method can not only help designers find the key assembly structure in complex mechanical assembly model, facilitate the function-structure designing and semantics analyzing, and thereby improve the efficiency of product knowledge reuse, but also assist in analyzing influence scope of key function part changing and optimization of the assembly process for complex mechanical assembly. Originality/value: The paper is the first to propose a method for key assembly structure identification in complex mechanical assembly, where the key function parts can be evaluated through a two-level evaluation model, and the key assembly structures are identified automatically based on complex network.