The increasing adoption of multimaterial components in the automotive industry reflects a growing demand for lightweight and multifunctional structures. Typically manufactured by injection overmolding, polymer-metal hybrid (PMH) parts combine the mechanical strength of metals with the low density of polymeric materials. This approach enables the integration of material-specific advantages, such as structural reinforcement and the incorporation of electronic circuits, into a single part, enhancing overall performance, functionality, and design flexibility. However, the reliability of PMH components depends critically on the quality of the adhesion between both materials, where ensuring strong and durable bonding remains a major concern. In this work, a case study inspired by an automotive application was developed to investigate the adhesion at the metal–polymer interface of a hybrid part. Metal inserts were subjected to various mechanical and chemical surface treatments and subsequently overmolded with a polymer matrix composite (PMC). The performance of the interface bonding was assessed using SEM, surface roughness measurements, and tensile loading. Sand-blasting, particularly when combined with etching treatments, significantly enhanced adhesion but was observed to markedly modify the metallic surface, which may raise concerns regarding corrosion behaviour and dimensional accuracy. Silane treatments, on the other hand, appeared to preserve surface integrity, making them a promising alternative. While these treatments introduce variability that can affect process repeatability, understanding and controlling these factors is essential for developing robust and scalable adhesion strategies for industrial contexts.

Background: Numerical simulation is becoming essential in the mechanical design of sheet metal components, requiring advanced material models, composed of many unknown parameters, to accurately describe complex material behavior. Traditionally, these parameters are identified through multiple quasi-homogeneous tests, each providing specific mechanical data on a particular strain state. The emergence of heterogeneous mechanical tests has revolutionized this process by enabling the capture of a wide range of strain states in a single experiment. Objective: This study focuses on the experimental analysis of three heterogeneous mechanical tests, previously studied numerically. The main objective is to confirm the quality and relevance of the mechanical deformation observed when using real data and evaluate the sensitivity of these tests to different high-strength steels. Methods: Uniaxial loading tests were conducted on three different specimen designs, using Stereo Digital Image Correlation to capture the mechanical fields on the surface. Multi-DIC systems were used to measure the out-of-plane behavior observed for a specimen design to increase the strain richness provided by the test. The repeatability of these tests is checked due to their complex designs. Results: The results show that the potential of heterogeneous mechanical tests remains unchanged when tested in real-world experimental settings. Conclusions: When combined with full-field measurement techniques, these can provide a wide range of mechanical behavior data from a single test, reducing the number of tests needed for advanced material characterization.

-Experimental investigation of heterogeneous mechanical tests GONÇALVES Mafalda, GUEGAN Briag, THUILLIER Sandrine, ANDRADE-CAMPOS António [button link="http