The analysis of polymeric sheet materials deformed by means of incremental sheet forming technologies has recently caught the attention of a number of research groups of the materials forming community. The versatility of the process, which allow manufacturing customised sheet components without the need of dedicated tools or dies, as well as the many advantages of polymers in terms of cost, recycling, material properties or biocompatibility, make its use suitable in many industrial sectors such as the automotive, the aerospace or the biomedical. In this global scenario, this paper presents an overall experimental investigation of polycarbonate sheets deformed by single point incremental forming, aiming the identification of the influence of the main process parameters in the material formability and the resulting mode of failure. The study is carried out in terms of principal strains that are evaluated within the material forming limit diagrams obtained independently by means of Nakajima tests. In order to provide more general conclusions, two different materials thicknesses are considered. The results allow establishing the forming limits of the polymeric sheet material and the failure mechanism in SPIF for each of the cases considered. Three main failure modes are assessed in the experiments: fracture by cracking, twisting and crazing. A general perspective of the influence of the process parameters in formability and the mode of failure is accomplished, pointing out that: (i) low thicknesses and higher step downs favor the appearance of twisting, (ii) most of the typical forming conditions in SPIF lead to failure by fracture in the absence of necking due to crack opening in mode I of fracture mechanics, and (iii) certain forming conditions promoting polymer degradation such as high spindle speeds and the consequent increase of temperature may be able to active mixed modes of failure in spifed polymeric sheets including crazing combined with fracture.

最近，借助增量片材成形技术对聚合物片材进行变形的分析引起了材料成形界众多研究小组的关注。该方法的多功能性使得无需专用工具或模具即可生产定制的片材组件，以及聚合物在成本，回收利用，材料特性或生物相容性方面的诸多优势，使其在许多工业领域均适用。作为汽车，航空航天或生物医学。在这种全球情况下，本文提出了对通过单点渐进成形变形的聚碳酸酯板进行的整体实验研究，旨在确定主要工艺参数对材料可成形性的影响以及由此导致的破坏模式。该研究是根据通过中岛试验独立获得的材料成形极限图中评估的主应变进行的。为了提供更一般的结论，考虑了两种不同的材料厚度。结果允许针对所考虑的每种情况确定聚合物片材的成形极限和SPIF中的破坏机理。实验中评估了三种主要的失效模式：开裂，扭曲和开裂。大致了解了工艺参数对可成形性和破坏方式的影响，并指出：（i）低厚度和较高的台阶降低了扭曲的外观，