Chenzhuo Li

• Bachelor of Engineering
• Beihang University

Rapid advances in biomedical applications and soft robotics demand load‐bearing soft materials that can be processed into complex 3D shapes. Direct ink writing (DIW) enables the fabrication of customizable shapes with locally varying compositions. Hydrogels that are formulated as microgels meet the rheological requirements that DIW imparts on the i...

In fracture mechanics, polyacrylamide hydrogel has been widely used as a model material in experiments due to its optical transparency, the brittle nature of its failure, and low Rayleigh wave velocity. Indeed, linear elastic fracture mechanics has been used successfully to model the fracture of polyacrylamide hydrogels. However, in soft materials...

In fracture mechanics, polyacrylamide hydrogels have been widely used as a model material for experiments, benefited from its optical transparency, fracture brittleness, and low Rayleigh wave velocity. To describe the brittle fracture in the hydrogels, linear elastic fracture mechanics comes as the first choice. However, in soft materials such as h...

Brittle solids typically fail by growth and propagation of a crack from a surface flaw. This process is modelled using linear elastic fracture mechanics, which parameterizes the toughness of a material by the critical stress intensity factor, or the prefactor of the singular stress field. This widely used theory applies for cracks that are planar,...

Background Obtaining accurate displacement measurements for large material deformation and/or rotation presents a distinct challenge to digital image correlation (DIC) due to cumulative and decorrelation errors, particularly near material boundaries. Objective We aim to accurately measure the deformation gradient tensor near boundary discontinuiti...

When brittle hydrogels fail, several mechanisms conspire to alter the state of stress near the tip of a crack, and it is challenging to identify which mechanism is dominant. In the fracture of brittle solids, a sufficient far-field stress results in the complete loss of structural strength as the material ‘unzips’ at the tip of a crack, where stres...

When brittle hydrogels fail, several mechanisms conspire to alter the state of stress near the tip of a crack, and it is challenging to identify which mechanism is dominant. In the fracture of brittle solids, a sufficient far-field stress results in the complete loss of structural strength as the material `unzips' at the tip of a crack, where stres...

Heatwave distortions, caused by unevenly distributed temperature and refractive index in the optical path, unavoidably occur in high-temperature digital image correlation (DIC) measurement. To eliminate these distortions, a multispectral DIC-aided reference sample compensation method is proposed. The proposed method first adheres a correcting trans...

Background An advanced two-dimensional digital image correlation (2D-DIC) using active imaging and telecentric imaging has been proposed to overcome the problems of out-of-plane motion and ambient light variation. Objective Here, the technique is further improved by combining built-in coaxial illumination and telecentric fluorescent imaging to prov...

Digital gradient sensing (DGS) is a non-contact and full-field optical measurement technique, which assesses mechanical behaviors of transparent materials or specular structures by measuring angular deflections of light rays. However, owing to the poor light-gathering capability of its imaging system, the dynamic performance of DGS is heavily restr...

High-throughput measurement of thermal deformation and determination of coefficient of thermal expansion (CTE) using a high-resolution digital single lens reflex (DSLR) camera and digital image correlation (DIC) is described. To mitigate the mosaic effect caused by the Bayer filter of DSLR cameras, a color image pre-processing method, which adjusts...

Fluorescent digital image correlation (DIC) has been implemented on monocular and binocular fluorescence microscopes for shape and deformation measurement at microscale and even nanoscale by tracking fluorescent particles. This technique, however, has not been used with regular optical imaging systems for DIC measurements in macroscale so far. In t...

Video extensometer assesses mechanical properties of materials by measuring their length changes under different loadings with combined use of video recording and image processing. In this Letter, an ultrasensitive video extensometer implemented on a single-camera dual field-of-view (dual FOV) telecentric imaging system is proposed. The method inte...

We propose a novel, flexible and easy-to-implement single-camera microscopic three-dimensional digital image correlation (3D-DIC) technique for accurate full-field shape, motion and deformation measurements at the microscale. The established microscopic 3D-DIC system comprises a single 3CCD color camera, a high magnification zoom lens, and a specia...