Thawing Methods Research Articles

Experimental Study on the Freeze–Thaw Characteristics of Clays with Different Initial Moisture Contents and Thawing Temperatures

Abstract To reveal the effects of the thawing temperature and initial moisture content on the freeze–thaw (F-T) characteristics of clays, F-T tests were performed on clays with three initial moisture contents (25 %, 30 %, and 35 %) at two thawing temperatures (25°C and 70°C). Changes in water content of specimens before and after F-T and the phenomena changes at the top surface of specimens after F-T were analyzed. The relationship between the change of water content and the pot-cover effect and surface cracking were discussed. The results showed that stable temperatures at the freezing of the specimens with initial moisture contents of 30 % and 35 % were 14.7 % and 79 %, respectively, both lower than that of the specimen with initial moisture contents of 25 %. With a thawing temperature of 70°C, the time to reach 0°C of the specimen was reduced by 35.9 % to 40.57 %, and the thaw settlement coefficient was reduced by 2.4 % to 4.75 %. When the temperature changes, the deformation of specimens also change and present certain hysteresis during F-T. The upwards net change occurred after F-T; at that time, the total water content inside the specimen decreased, the water content in the upper part of the specimen decreased, and the water content in the lower part of the specimen increased. At the same time, the pot-cover effect occurred on the top surface of the specimen, and the cracking appeared on the top surface and inside the specimen. More moisture migrated upwards to the top of the specimens and the mass of water in the specimen after F-T was less with a thawing temperature of 70°C. Based on the test results, some suggestions are provided for construction of cross passages with AGF and the forced thawing method.

Developments in Radiofrequency Processing Applications on Food of Animal Origin

Radio frequency (RF) treatment is one of the novel dielectric heating techniques for foods. It is an indirect process whereby electrical energy is initially transformed into electromagnetic radiation, which then generates heat within the food. Radiofrequency heating has been found some advantages like rapid heating or deep penetration into food compare to conventional methods. Traditional heat treatments applied to animal products can lead to quality losses, color and texture changes, overheating problems and other undesirable side effects. RF treatment has the potential to minimize these problems, improve organoleptic quality, reduce process time and save energy. Recently, the most investigated methods for animal origin foods are RF pasteurization/sterilization, RF-supported thawing methods, RF heating or cooking and the results obtained are promising. Radiofrequency technique is also investigated for following purposes; blanching, post-bake drying, roasting and disinfection. The new generation of RF studies explore other aspects, including the discovery of dielectric properties of foods, the evaluation of efficiency and quality effects, environmental sustainability of RF technologies and the improvement of RF system performance. Also combined systems are investigated such as radiofrequency-assisted cryogenic freezing. This paper reviewed principles of RF, overview situation of RF treatment methods and recent literature on RF applications on food of animal origin.

Preparation and characterization of transparent cellulose nanocrystal film using freeze–thaw technique

The objective of the study was to prepare self-assembled transparent cellulose nanocrystal (CNC) films utilizing freeze–thaw technique. To date, self-assembled transparent CNC solid film can be obtained through chemical doping. Here, an easy alternative route was demonstrated to produce such film without chemical modification. It was found that the freeze–thaw method completely eliminated the chiral nematic structure, resulting in completely transparent films without structural color. Detailed internal structure characterization using SEM, XRD, and UV–Vis spectroscopy coupled with optical property analysis revealed a remarkable improvement in the clarity and sharpness of freeze–thaw based CNC films without compromising transmittance and haze, showing promise of freeze–thaw based CNC films in packaging and coating applications.Graphical abstract

Quality Differences in Frozen Mackerel According to Thawing Method: Potential Classification via Hyperspectral Imaging

Seafood quality preservation remains a critical focus in the food industry, particularly as the freeze–thaw process significantly impacts the freshness and safety of aquatic products. This study investigated quality changes in frozen mackerel subjected to two thawing methods, room temperature (RT) and running water (WT), and assessed the potential of hyperspectral imaging (HSI) for classifying these methods. After thawing, mackerel samples were stored at 5 °C for 21 days, with physicochemical, textural, and spectroscopic analyses tracking quality changes and supporting the development of a spectroscopic classification model. Compared with the WT method, the RT method delayed changes in key quality indicators, including pH, total volatile basic nitrogen (TVB-N), and total viable count (TVC), by 1–2 days, suggesting it may better preserve initial quality. Texture profile analysis showed similar trends, supporting the benefit of RT in maintaining quality. A major focus was on using HSI to assess quality and classify thawing methods. HSI achieved high classification accuracy (Rc2 = 0.9547) in distinguishing thawing methods up to three days post-thaw, with 1100, 1200, and 1400 nm wavelengths identified as key spectral markers. The HIS’s ability to detect differences between thawing methods, even when conventional analyses showed minimal variation, highlights its potential as a powerful tool for quality assessment and process control in the seafood industry, enabling detection of subtle quality changes that traditional methods may miss.

A COMPARATIVE STUDY OF THE PRODUCTION COSTS OF HYDROPHOBIC OINTMENTS, HYDROPHILIC OINTMENTS, AND GELS IN RELATION TO DRUG FORMULATION STABILITY

Povidone – iodine has antiseptic properties for wound healing. This research makes antiseptic preparations in semi-solid dosage form with different bases used. This research aims to find out whether the different bases in the formula used can affect its stability and how much it costs for each formula. Formula 1 with a hydrocarbon base, formula 2 with a hydrophilic base, formula 3 gel with a Na-CMC base. The stability of the three formulas was observed using the freeze - thaw method with different temperatures for 18 days of storage and observed organoleptically, homogeneity, spreadability, pH viscosity and then processed using one way ANOVA and I-MR control charts. The research results showed that the different bases in the formula had a significant effect on the spreadability, pH and viscosity values ​​with a significant value of 0.000. Differences in formula also affect organoleptic results and homogeneity. Formula 2 has the best stability based on the results of the tests carried out. In terms of costs, Formula 2 has greater raw material costs compared to Formula 1 and Formula 3. Keywords: Antiseptic, cost and stability

Preparation of strong, tough and highly ion-conductive nanocellulose hydrogels based on freeze–thaw cycles: performance evaluation under different freezing temperatures

Abstract Rapid and effective preparation of hydrogels with excellent properties by cyclic freezing–thawing has remained an enormous challenge as hydrogels prepared using traditional freeze–thaw methods demonstrate poor, unstable and unalterable mechanical properties. In this study, an innovative method was introduced to develop a nanocellulose hydrogel with excellent properties via cyclic freezing–thawing and ionic cross-linking, and various methods were used to characterise the structure and properties of the hydrogel. The results showed that hydrogen and ester bonds existed in the soy hull nanocellulose–sodium alginate–calcium chloride (SHNC/SA/Ca2+) hydrogel and that the internal structure of the hydrogel changed from a lamellar to three-dimensional network structure owing to low temperature, increasing the cross-linking density of SHNC and SA and enhancing the mechanical strength of the hydrogel. Meanwhile, the SHNC/SA/Ca2+-4 hydrogel demonstrated excellent elongation (804 %), viscoelasticity (storage modulus = 89.6 kPa), mechanical strength (tensile strength = 0.59 MPa, compressive strength = 1.52 MPa), ionic conductivity (3.84 S/m), transparency (54 %), anti-ultraviolet properties and fatigue resistance. The simple preparation process, excellent performance and three-dimensional porous network structure of the nanocellulose hydrogel offer broad application prospects in many fields.

The Effect of Different Freezing and Thawing Methods on Physicochemical, Sensory, and Flavor Characteristics of Korean Native Chicken Breast

The Effect of Different Freezing and Thawing Methods on Physicochemical, Sensory, and Flavor Characteristics of Korean Native Chicken Breast

Optimization of Polysaccharide Extraction from Polygonatum cyrtonema Hua by Freeze–Thaw Method Using Response Surface Methodology

Polygonatum cyrtonema polysaccharides have a variety of pharmacological effects. The commonly used extraction methods include traditional hot water extraction, alkaline extraction, enzymatic hydrolysis method, ultrasonic-assisted extraction, etc., but there are problems such as low yield, high temperature, high cost, strict extraction conditions, and insufficient environmental protection. In this study, crude polysaccharide extraction from the Polygonatum cyrtonema Hua was performed using the freeze–thaw method. Response surface methodology (RSM), based on a three-level, three-variable Box–Behnken design (BBD), was employed to obtain the best possible combination of water-to-raw material ratio (A: 30–50), freezing time (B: 2–10 h), and thawing temperature (C: 40–60 °C) for maximum polysaccharide extraction. Using the multiple regression analysis and analysis of variance (ANOVA), the experimental data were fitted to a second-order polynomial equation and were used to generate the mathematical model of optimization experiments. The optimum extraction conditions were as follows: a water-to-raw material ratio of 36.95:1, a freezing time of 4.8 h, and a thawing temperature of 55.99 °C. Under the optimal extraction conditions, the extraction rate of Polygonatum cyrtonema Hua polysaccharide (PCP) was 65.76 ± 0.32%, which is well in close agreement with the value predicted by the model, 65.92%. In addition, PCP has significant antioxidant activity. This result shows that the freeze–thaw method can improve the extraction efficiency, maintain the structural integrity of polysaccharides, simplify the extraction process, promote the dispersion of polysaccharides, and is suitable for large-scale industrial production.

Changes in the Objective Indices Related to Meat Quality of Porcine Longissimus Dorsi Induced by Different Thawing Methods.

The quality of frozen pork is adversely affected upon thawing. In this study, the influence of various thawing methods for frozen pork, including cold water (18 °C), room temperature (18 °C), and refrigeration (4 °C) thawing, on physicochemical and nutrient substances were examined. The pork samples (a Chinese local breed: Anqing six-end-white pigs), which were thawed through the above conditions, were compared with controls (fresh porcine longissimus dorsi). Analyses were carried out to determine porcine longissimus dorsi shear force, pH value, crude protein content, antioxidant capacity, amino acid content, and fatty acid content. The results indicated that the shear force, pH value, crude protein content, total antioxidant capacity (T-AOC), and total superoxide dismutase (T-SOD) content of the porcine longissimus dorsi muscle significantly decreased via the three thawing methods compared with the control group (p < 0.05). However, malondialdehyde (MDA) content, intramuscular fat content, inosinate and cholesterol content, essential amino acid content, and umami amino acid proportion in the cold thawing group were not significantly different from the control group (p > 0.05), but there were significant differences between the other two groups. The MDA content of the air thawing and hydrostatic thawing groups significantly increased compared with the control group (p < 0.05), with it being 42.6% and 50.8% higher than the control group, respectively. In addition, the monounsaturated fatty acid content in the pork subjected to the three thawing methods significantly increased compared with the control group (p < 0.05), and the monounsaturated fatty acid content after cold thawing and hydrostatic thawing increased by 18.2% and 21.6%, respectively. In conclusion, refrigeration had less influence on the quality of the Anqing six-end-white pork and was the most suitable thawing method. This study provides a theoretical reference for frozen pork preservation for improving food quality and availing its economic benefits.

Preparation of a Porous Spherical Adsorbent by Oil-In-Water-In-Oil Emulsion Polymerization for Phycocyanin Adsorption

ABSTRACT Phycocyanin is a protein with potential in food and medical applications. A porous spherical adsorbent was prepared by oil-in-water-in-oil emulsion polymerization. Oil and water phases containing surfactants and monomers, respectively, were emulsified, and the prepared emulsion was added to the oil phase to polymerize the porous spherical adsorbent. The concentration ratio of N,N-dimethylacrylamide and 2-dimethylaminoethylmethacrylate (DMAEMA) in the water phase was changed. The obtained spherical adsorbent had a size of about 150 μm and a water content of 90%, with macropores of several micrometers. Phycocyanin (20 kDa) of Nostoc commune was leached by the freeze and thaw method to prepare the solution. The adsorption data of the batch and column modes were evaluated by ordinary differential and partial differential equations, respectively, considering competitive adsorption, to obtain parameters of the mass transfer coefficient and saturated adsorption capacity. In the b\ sfer coefficient of phycocyanin decreased by about one-third, but the saturated adsorption capacity increased three-fold. In the continuous flow column, leached biomacromolecules other than phycocyanin had greater parameters of mass transfer and capacity. To prepare an adsorbent for the biomacromolecules, selective adsorption sites in the polymer matrix should be designed and prepared.

Optimization of pulsed electric fields-assisted thawing process conditions and its effect on the quality of Zhijiang duck meat

Freezing storage is a common preservation method for industrialized duck meat. However, both the frozen storage and thawing processes of meat can affect meat quality. Therefore, appropriate thawing methods are crucial for maintaining good meat quality. In this study, a pulsed electric field (PEF) was used for thawing zhijiang duck meat and the freshed duck meats were used as control. Optimization of the PEF-assisted thawing process and its effect on the quality of zhijiang duck meat were analyzed. Our data showed that the shear force in the 2 kV/cm PEF-assisted thawing group was the lowest in PEF-assisted thawing groups. The color of zhijiang duck meat in the 2 kV/cm PEF-assisted thawing group was optimal. The 2 kV/cm PEF-assisted thawing could improve the texture characteristics of zhijiang duck meat and enhance water holding capacity of zhijiang duck meat. PEF-assisted thawing could better maintain the microstructure of zhijiang duck meat. Our data showed that if the intensity or duration of PEF treatment is too high, the quality of duck meat will actually decrease. Therefore, appropriate parameters should be selected in practical applications, which will provide a reference for the application of PEF-assisted thawing on the market.

Ultrasound-assisted improvement of thawing quality of Tibetan pork by inhibiting oxidation

The challenge of meat quality degradation due to transportation difficulties in high-altitude plateaus underscores the importance of an efficient thawing process for Tibetan pork to ensure its quality. This study compared four thawing methods ultrasound thawing (UT), refrigerator thawing (RT), hydrostatic thawing (HT), and microwave thawing (MT) to assess their impact on the quality of Tibetan pork, focusing on thawing loss, tenderness, color variation, and alterations in protein secondary structure and moisture content. Additionally, the study examined the impact of thawing on the metabolites of Tibetan pork using metabolomics techniques. The results indicated that UT yielded the highest quality samples. UT significantly accelerated the thawing rate and had minimal impact on tenderness compared to traditional thawing methods. Moreover, protein and lipid oxidation levels were reduced by UT treatment. Furthermore, it enhanced the binding capacity of protein and water molecules, reduced drip loss, and maintained meat color stability. What’s more, amino acid metabolites such as l-glutamic acid, l-proline, oxidized glutathione, and 1-methylhistidine played a significant role in thawing oxidation in Tibetan pork, exhibiting a positive correlation with protein oxidation. UT resulted in a notable decrease in the levels of hypoxanthine and 2-aminomethylpyrimidine, contributing to the reduction of bitterness in the thawed meat and consequently enhancing the freshness of Tibetan pork. This study offers novel insights into understanding the biological changes occurring during the thawing process, while also furnishing a theoretical framework and technical assistance to improve the quality of Tibetan pork and propel advancements in food processing technology.

Frost Resistance Differences of Concrete in Frequent Natural Freeze–Thaw versus Standard Rapid Method

In order to find the anti-freezing durability differences between concrete in the frequent natural freeze–thaw conditions in the northwest of Sichuan Province, China, and concrete in the rapid freeze–thaw conditions of the standard rapid method, the typical temperature and humidity of the northwest of Sichuan Province were simulated. The results showed that the average number of freeze–thaw cycles in the northwest of this province can reach up to 150 per year. The relative dynamic modulus of C30 ordinary concrete, which is 100% pre-saturated, still remained above 90% after 450 cycles in simulated environments. However, during the rapid freeze–thaw test, even the C30 air-entrained concrete failed after 425 cycles. Compared to the saturation degree of concrete itself, the continuous replenishment of external moisture during freeze–thaw cycles is a key factor affecting the frost resistance of concrete. Rapid freeze–thaw reduces the number of the most probable pore sizes in ordinary concrete, and the pore size distribution curve tends to flatten. The reduction rate of the surface porosity of air-entrained concrete before and after rapid freeze–thaw is only about one third of that of ordinary concrete.

A high-precision and near-zero residue laser-controlled gel propellant

Micro-nano satellites, with their advantages of small size, low power consumption, short development cycles, and capability for formation flying and networking, play a significant role in scientific research, national defense, and commercial applications. However, currently developed micro-nano satellites globally possess very limited maneuverability and lack effective attitude and orbit propulsion control. Solid propellants can offer some advantages such as high energy density and low cost, and they are extensively used in micro-and nano satellite propulsion systems. However, most of these propellants exhibit poor controllability and produce massive amounts of residual by-products. Laser-controlled gel propellants have been confirmed to be the most effective solution to address these issues in this study. The present study exhibits the preparation of ADN-based laser-controlled gel propellants using the freeze–thaw method and their controllable combustion characteristics under laser irradiation. The results show that the ignition delay time of gel propellants decreases from 93.0 ms to 34.6 ms, the extinction delay time is stable at around 2 ms, and the average burning rate increases from 0.6 mm/s to 1.5 mm/s under continuous laser irradiation with the power density ranging from 0.6 to 1.3 W/mm2. The average utilization rate of gel propellant is as high as 99.2 %. Upon testing, the residual solid matter was identified as unreacted propellant that had not been irradiated by the laser. Laser-controlled gel propellants represent a new type of energetic material that can be modulated to control its ignition, extinction, and burning rate. These capabilities overcome the challenges associated with the inability of traditional chemical propellants to extinguish and restart, thereby fulfilling the propulsion system requirements of micro-nano satellites.

Self-assembly polysaccharide network regulated hydrogel sensors with toughness, anti-freezing, conductivity and wide working conditions

Ionic conducting hydrogel acted as a promising candidate in flexible electronic device, however, the intrinsic properties of weak mechanical strength, conductivity and environmental instability still are the challenging task. Herein, an assembled polysaccharide network (acetylated distarch phosphate) regulated polyvinyl alcohol (PVA/ADSP) hydrogel is fabricated via one-step freeze–thaw method, the stress, elongation at break, elastic modulus, and toughness could reach 2.26 MPa, 818.60 %, 0.95 MPa, and 12.23 kJ/m3, respectively. At the same time, the binary solution interlocked structure and salt are introduced into the PVA/ADSP hydrogel realizing the great environmental stability (water-retention and anti-freezing) and conductivity (3.59 S/m). PVA/ADSP hydrogel act as strain sensor presenting the great responsibility (128 ms), strain sensitivity (GF=1.82 at 350–500 % of strain) and durability. On account of the excellent sensing characteristics, the PVA/ADSP hydrogel could reliably, accurately and consistently detect most of human exercises and subtle physiological activities (electrocardiography) in real-time. Moreover, PVA/ADSP hydrogel is also utilized to control robotic hand realizing the human–machine interaction. This work provides a novelty regulated approach for conducting hydrogel via self-assembled polysaccharide network, which contributes to the innovative advancement of flexible wearable electronics.

Effect of Water Bath versus Refrigerator Thaw on Cryoprecipitate Fibrinogen and Factor VIII Content Using a Pre-Pooled Plasma Experimental Approach

&lt;b&gt;&lt;i&gt;Introduction:&lt;/i&gt;&lt;/b&gt; Originally developed as a form of factor VIII concentrate, cryoprecipitate’s primary clinical use has changed to treat fibrinogen deficiency as highlighted by recent approval of pathogen-reduced cryoprecipitated fibrinogen concentrates. The methodology by which frozen plasma is thawed during cryoprecipitate manufacturing is not standardized. This study compared plasma thawing techniques on cryoprecipitate fibrinogen and factor VIII levels. &lt;b&gt;&lt;i&gt;Methods:&lt;/i&gt;&lt;/b&gt; A matched pairwise experimental design was employed across three experiments to compare plasma thawing approaches (water bath or 24–48 h refrigerator). Each experiment involved the creation of 10 sets of ten homogenous frozen plasma pools which were then used to manufacture 10 pairs of cryoprecipitate pools differing only by assigned plasma thawing method. Total cryoprecipitate fibrinogen and factor VIII content between plasma thawing methods were compared using matched &lt;i&gt;t&lt;/i&gt;-testing within each experiment. &lt;b&gt;&lt;i&gt;Results:&lt;/i&gt;&lt;/b&gt; Compared to water bath thawing, 24-h refrigerator thawing led to significantly higher cryoprecipitate fibrinogen content (2,554 mg vs. 1,824 mg; &lt;i&gt;p&lt;/i&gt; &amp;lt; 0.001) and significantly lower cryoprecipitate factor VIII content (601 IU vs. 709 IU; &lt;i&gt;p&lt;/i&gt; &amp;lt; 0.001). Longer refrigerator thaw times (36 and 48 h) led to significantly higher cryoprecipitate fibrinogen content than 24-h refrigerator thaw (3,180 mg vs. 2,956 mg and 2,893 mg vs. 2,483 mg, respectively; &lt;i&gt;p&lt;/i&gt; = 0.01–0.03). &lt;b&gt;&lt;i&gt;Conclusion:&lt;/i&gt;&lt;/b&gt; Using homogenous frozen plasma units in a matched pairwise experimental design, refrigerator plasma thawing led to superior cryoprecipitate fibrinogen yields and inferior cryoprecipitate factor VIII yields. When maximizing cryoprecipitate fibrinogen yields, refrigerator plasma thawing, and in particular longer thawing times (36–48 h), should be considered.

Ultrasonic technology for predicting beef thawing degree and endpoint

Precise control and accurate endpoint determination in the thawing of frozen beef are vital for maintaining its quality and safety in the food industry. Traditional thawing methods, which are time-controlled, often lead to inconsistencies like under or over-thawing, adversely affecting texture, color, nutritional value, and increasing the risk of microbial contamination. This study introduces a novel, non-destructive approach using ultrasonic signals and ultrasonic velocity for the quantification of beef thawing. It involves analyzing thermal images of beef cross-sections to assess thawing levels and gathering ultrasonic data at various thawing stages. Machine learning algorithms, including KNN, ANN, Extra-Trees, and LightGBM, were employed to develop prediction models that accurately identify the thawing endpoint. The models exhibit high accuracy, with R^2 values exceeding 0.9, some reaching as high as 0.986. This method represents a significant advancement in non-destructive quality control, enhancing safety and quality management in the beef processing sector.

The Influence of Various Freezing-thawing Methods of Skin on Drug Permeation and Skin Barrier Function.

The selection of skin is crucial for the in vitro permeation test (IVPT). The purpose of this study was to investigate the influence of different freezing-thawing processes on the barrier function of skin and the transdermal permeability of granisetron and lidocaine. Rat and hairless mouse skins were thawed at three different conditions after being frozen at -20℃ for 9days: thawed at 4℃, room temperature (RT), and 32℃. There were no significant differences in the steady-state fluxes of drugs between fresh and thawed samples, but compared with fresh skin there were significant differences in lag time for the permeation of granisetron in rat skins thawed at RT and 32℃. Histological research and scanning electron microscopy images showed no obvious structural damage on frozen/thawed skin, while immunohistochemical staining and enzyme-linked immunosorbent assay for the tight junction (TJ) protein Cldn-1 showed significantly impaired epidermal barrier. It was concluded that the freezing-thawing process increases the diffusion rate of hydrophilic drugs partly due to the functional degradation of TJs. It's recommended that hairless, inbred strains and identical animal donors should be used, and the selected thawing method of skin should be validated prior to IVPT, especially for hydrophilic drugs.

Effect of different thawing methods on the quality of goat liver

The experiment was conducted to find out the effect of different thawing methods like ambient temperature thawing, refrigerator thawing and tap water thawing on the quality of goat liver. Sensory evaluation, proximate components, physico-chemical quality, biochemical properties and microbiological tests. Six goat livers were collected from a local slaughterhouse. Liver samples were preserved under freezing condition (-20°C) for 3 months after fresh evaluation. After evaluation of thawed liver, color, odor, juiciness, and tenderness were significantly (P&lt;0.05) different with maximum values of color and odor found in refrigerator thawing while maximum juiciness and tenderness value found in ambient temperature thawing. DM and Ash contents were not significantly differed (P&gt;0.05); however, the highest value found in refrigerator thawing within the three thawing methods. CP content was significant (P&lt;0.05) different among the different thawing methods. EE content differed significantly (P&lt;0.05), although less amount of EE content was found in refrigerator thawing. There was no significant (P&gt;0.05) variation of pH value on studied thawing methods. Thawing loss, WHC and colour measurement significantly (P&lt;0.05) differed with the different thawing methods, while thawing loss of tap water thawing, WHC value of ambient temperature thawing and colour value of refrigerator thawing were found in maximum level. TBARS value was significantly varied among the different thawing methods where the minimum result found in tap water thawing but maximum result found in ambient temperature thawing. TVC, TCC and TYMC comparatively more number found in ambient temperature thawing but less number found in refrigerator thawing. The lowest number of microbial counts found in refrigerator thawing. It may conclude that refrigerator thawing is the best thawing method to determine the quality of goat liver than others in this experimental condition.

Thermo‐hydro‐mechanical coupled material point method for modeling freezing and thawing of porous media

AbstractClimate warming accelerates permafrost thawing, causing warming‐driven disasters like ground collapse and retrogressive thaw slump (RTS). These phenomena, involving intricate multiphysics interactions, phase transitions, nonlinear mechanical responses, and fluid‐like deformations, and pose increasing risks to geo‐infrastructures in cold regions. This study develops a thermo‐hydro‐mechanical (THM) coupled single‐point three‐phase material point method (MPM) to simulate the time‐dependent phase transition and large deformation behavior arising from the thawing or freezing of ice/water in porous media. The mathematical framework is established based on the multiphase mixture theory in which the ice phase is treated as a solid constituent playing the role of skeleton together with soil grains. The additional strength due to ice cementation is characterized via an ice saturation‐dependent Mohr–Coulomb model. The coupled formulations are solved using a fractional‐step‐based semi‐implicit integration algorithm, which can offer both satisfactory numerical stability and computational efficiency when dealing with nearly incompressible fluids and extremely low permeability conditions in frozen porous media. Two hydro‐thermal coupling cases, that is, frozen inclusion thaw and Talik closure/opening, are first benchmarked to show the method can correctly simulate both conduction‐ and convection‐dominated thermal regimes in frozen porous systems. The fully THM responses are further validated by simulating a 1D thaw consolidation and a 2D rock freezing example. Good agreements with experimental results are achieved, and the impact of hydro‐thermal variations on the mechanical responses, including thaw settlement and frost heave, are successfully captured. Finally, the predictive capability of the multiphysics MPM framework in simulating thawing‐triggered large deformation and failure is demonstrated by modeling an RTS and the settlement of a strip footing on thawing ground.